gtk: Update a comment

src/_sass/gtk/_common-3.20.scss

@@ -1116,8 +1116,8 @@ headerbar {

                                
                                
                                
                            
                                
                                    
                                        
                                            1116  
                                              }
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
                                            1117  
                                            
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
                                            1118  
                                              &.selection-mode {
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        1119 -
                                            // FIXME: 0.00001s is workaround for transition bug of gtk+ 3.22
                                        
                                        
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        1120 -
                                            // see https://bugzilla.gnome.org/show_bug.cgi?id=774064
                                        
                                        
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        1119 +
                                            // 0.00001s was a workaround for https://gitlab.gnome.org/GNOME/gtk/issues/698
                                        
                                        
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        1120 +
                                            // but let's keep it for backwards compatibility.
                                        
                                        
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
                                            1121  
                                                transition: background-color 0.00001s $longer_duration, color $longer_duration $deceleration_curve;
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
                                            1122  
                                                animation: header_ripple_effect $longer_duration $deceleration_curve;
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
                                            1123  
                                                box-shadow: $shadow_1, inset 0 1px $alt_highlight_color;