Qt5: set win32-msvc2010 developer-build angle Windows 7 enforcing

This is passing.  Make sure it stays that way.

Change-Id: I7bb5e7d11ba1ae90541fd8b2bb44536c190fbcc7
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>