Remove commented out line from the dnd sample.

No real changes, just remove the unnecessary line and its outdated comment
(wxPaintDC::Clear() can be called in wxGTK, it's just not useful).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75589 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/dnd/dnd.cpp

@@ -1084,7 +1084,6 @@ void DnDFrame::OnPaint(wxPaintEvent& WXUNUSED(event))
     GetClientSize( &w, &h );
 
     wxPaintDC dc(this);
-    // dc.Clear(); -- this kills wxGTK
     dc.SetFont( wxFont( 24, wxDECORATIVE, wxNORMAL, wxNORMAL, false, wxT("charter") ) );
     dc.DrawText( wxT("Drag text from here!"), 100, h-50 );
 }