Remove code to draw rounded bottom window corners which is not effective.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11522 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

src/drivers/Cocoa/Fl_Cocoa_Window_Driver.cxx

@@ -109,10 +109,6 @@ void Fl_Cocoa_Window_Driver::draw_begin()
     CGContextSaveGState(gc);
 # endif
   }
-  if ( fl_mac_os_version >= 100600 ) {
-    // for Mac OS X 10.6 and above, make window with rounded bottom corners
-    Fl_X::clip_to_rounded_corners(gc, pWindow->w(), pWindow->h());
-  }
 }