Remove obsoleted comments

include/wx/propgrid/propgridiface.h

@@ -187,9 +187,6 @@ public:
     // Returns true if successful or if there was no selection. May
     // fail if validation was enabled and active editor had invalid
     // value.
-    // In wxPropertyGrid 1.4, this member function used to send
-    // wxPG_EVT_SELECTED. In wxWidgets 2.9 and later, it no longer
-    // does that.
     bool ClearSelection( bool validation = false );
 
     // Resets modified status of all properties.