Fix error message about credential
Fix error message about credential

TrivialFix

Change-Id: I530ad1511f550d681d7aad480b34c3391ada38fb

Juniper/tempest,bigswitch/tempest,masayukig/tempest,sebrandon1/tempest,openstack/tempest,cisco-openstack/tempest,bigswitch/tempest,Tesora/tesora-tempest,vedujoshi/tempest,openstack/tempest,vedujoshi/tempest,Juniper/tempest,cisco-openstack/tempest,masayukig/tempest,sebrandon1/tempest,Tesora/tesora-tempest