Qbs: Do not list Qbs steps in non-Qbs projects

They can not work there anyway.

Change-Id: Ic643ae7e35ad599ffb3928530eafb6ec537f3f04
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Ignore unconfigured VCS

Change-Id: I4a63734793debfcb37283257bb7cbf4b1153197f
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>