Utils: Pile more hacks onto our "QTipLabel"

The moc files "#include <memory>" these days. You cannot do that from
within a custom namespace or funny things will happen. Therefore,
include it already before the namespace.

Change-Id: I34f808cd22634c85878658ec921ca31649fb37c3
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/tooltip/tips.cpp

@@ -43,6 +43,8 @@
 #include <QPaintEvent>
 #include <QVBoxLayout>
 
+#include <memory>
+
 namespace Utils {
 namespace Internal {