Ensures mongodb configuration only happens if mongodb is needed
Ensures mongodb configuration only happens if mongodb is needed

Change-Id: I7e9eb665275bd48d9c079934cc01ba62b5f59e16

trozet/tripleo-heat-templates,trozet/opnfv-tht,bcrochet/tripleo-heat-templates,bcrochet/tripleo-heat-templates,rdo-management/tripleo-heat-templates,trozet/opnfv-tht,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates,trozet/tripleo-heat-templates,trozet/opnfv-tht,wyg3958/tripleo-heat-templates,rdo-management/tripleo-heat-templates,openstack/tripleo-heat-templates,wyg3958/tripleo-heat-templates,bcrochet/tripleo-heat-templates,openstack/tripleo-heat-templates