Correctly delete users.
Correctly delete users.

Fixes: bug #1081255
Change-Id: Idc9809d0a2b3c0ba6742aacaba58ddcfd892300e

metacloud/python-troveclient,openstack/python-troveclient,citrix-openstack/build-python-troveclient,Tesora/tesora-python-troveclient,cp16net/python-troveclient,metacloud/python-troveclient,cp16net/python-troveclient,citrix-openstack/build-python-troveclient,openstack/python-troveclient,citrix-openstack-build/python-troveclient,Tesora/tesora-python-troveclient,citrix-openstack-build/python-troveclient