Revert "Fixed warning message if QMetaObjectCleanUp::setMetaObject is invoked twice."

because of wrong reference to bug 1887.
This reverts commit 41f30477dd.

src/kernel/qmetaobject.cpp

@@ -1244,7 +1244,7 @@ QMetaObjectCleanUp::~QMetaObjectCleanUp()
 void QMetaObjectCleanUp::setMetaObject( QMetaObject *&mo )
 {
 #if defined(QT_CHECK_RANGE)
-    if (metaObject && metaObject != &mo)
+    if ( metaObject )
 	qWarning( "QMetaObjectCleanUp::setMetaObject: Double use of QMetaObjectCleanUp!" );
 #endif
     metaObject = &mo;