Added check for tqApp pointer in TQWidget destructor

Necessary for the application to shut down properly

Signed-off-by: ormorph <roma251078@mail.ru>
(cherry picked from commit c55ef27a2c)

src/kernel/qwidget.cpp

@@ -988,7 +988,7 @@ TQWidget::~TQWidget()
 	    tqApp->quit();
     }
 
-    if ( hasFocus() )
+    if ( tqApp && hasFocus() )
         clearFocus();
 
     if ( isTopLevel() && isShown() && winId() )