Sync oslo strutils module
Sync oslo strutils module

Changes -
 * Make strutils.mask_password more secure

Change-Id: Ib2bdfb9753188bdbd0fd59c43fb780d1cfd76eb3

citrix-openstack-build/python-saharaclient,citrix-openstack-build/python-saharaclient,citrix-openstack-build/python-saharaclient,openstack/python-saharaclient