adding else statement with empty string starting ansible 2.X it require a else statement.
adding else statement with empty string
starting ansible 2.X it require a else statement.

Closes-bug: #1588941
Change-Id: I3f12be8de75ddcebf28a077c361a9206b36aafb0

dardelean/kolla-ansible,mandre/kolla,stackforge/kolla,intel-onp/kolla,mrangana/kolla,dardelean/kolla-ansible,openstack/kolla,nihilifer/kolla,mrangana/kolla,rahulunair/kolla,coolsvap/kolla,mandre/kolla,coolsvap/kolla,GalenMa/kolla,coolsvap/kolla,stackforge/kolla,GalenMa/kolla,dardelean/kolla-ansible,nihilifer/kolla,openstack/kolla,rahulunair/kolla,intel-onp/kolla,stackforge/kolla,mandre/kolla