Disabled the dialogs that might show up when exiting on Windows

wxWidgets logs errors internally. When the wxLogNull object is destroyed, the default log object will be effective. Logs are displayed by calling MessageBox in a GUI application by default.

src/xmlcopyeditor.cpp

@@ -221,8 +221,6 @@ MyApp::MyApp()
 
 MyApp::~MyApp()
 {
-	ThreadReaper::get().clear();
-
 	delete checker;
 	delete server;
 }
@@ -1095,6 +1093,8 @@ MyFrame::MyFrame (
 
 MyFrame::~MyFrame()
 {
+	ThreadReaper::get().clear();
+
 	std::vector<wxString>::iterator it;
 	for ( it = tempFileVector.begin(); it != tempFileVector.end(); it++ )
 		wxRemoveFile ( *it );