Push down forcesuccess for macx-clang_no-framework_OSX_10.8

So that we can disable forcesuccess on each project as soon as it is
confirmed as passing.

Task-number: QTQAINFRA-608
Change-Id: I5187020016a27ac4fef80121baec4c9b3d6a823b
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>
Reviewed-by: Simo Fält <simo.falt@digia.com>