Add Debian image default user
Add Debian image default user

Change-Id: I65035814ce5c720f0f07c771f22875f0cdb0181e

Akasurde/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,Akasurde/openstack-manuals,potsmaster/openstack-manuals,kairoaraujo/openstack-manuals,saeki-masaki/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,saeki-masaki/openstack-manuals,potsmaster/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,gongysh2004/openstack-manual,gongysh2004/openstack-manual