Include moc of qnamespace.h in qobject.cpp

Change-Id: I84e363d735b443cb9beefffd14b8bd4b39b00840
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

src/corelib/kernel/qobject.cpp

@@ -5079,4 +5079,5 @@ bool QMetaObject::Connection::isConnected_helper() const
 
 QT_END_NAMESPACE
 
+#include "moc_qnamespace.cpp"
 #include "moc_qobject.cpp"