Remove no longer functional workaround

This workaround is no longer effective with the new system handler
method of handling keyboard events. The bug has also been fixed
in upstream FLTK, further making it pointless.

vncviewer/DesktopWindow.cxx

@@ -387,15 +387,6 @@ int DesktopWindow::handle(int event)
     }
     // Continue processing so that the viewport also gets mouse events
     break;
-
-  case FL_SHORTCUT:
-    // Sometimes the focus gets out of whack and we fall through to the
-    // shortcut dispatching. Try to make things sane again...
-    if (Fl::focus() == NULL) {
-      take_focus();
-      Fl::handle(FL_KEYDOWN, this);
-    }
-    return 1;
   }
 
   return Fl_Window::handle(event);