Fix error message about credential
TrivialFix
Change-Id: I530ad1511f550d681d7aad480b34c3391ada38fb
diff --git a/tempest/common/credentials_factory.py b/tempest/common/credentials_factory.py
index 58157ef..3923aec 100644
--- a/tempest/common/credentials_factory.py
+++ b/tempest/common/credentials_factory.py
@@ -133,7 +133,7 @@
def get_creds_by_roles(self, roles, force_new=False):
msg = "Credentials being specified through the config file can not be"\
" used with tests that specify using credentials by roles. "\
- "Either exclude/skip the tests doing this or use either an "\
+ "Either exclude/skip the tests doing this or use either a "\
"test_accounts_file or dynamic credentials."
raise exceptions.InvalidConfiguration(msg)