The direct import of the auth plugin
'keystone.auth.plugins.oauth1.OAuth' is deprecated since
Liberty.
The entrypoint should only be defined in case there is a
need to override the default implementation with a custom
class.
A closer inspection to the code confirms that:
70c9dd8256/keystone/conf/auth.py (L63)
Closes-Bug: #1837109
Change-Id: Icbad28cdefbccb6e6499ad4e19ad0d6bfaeff677