core.cli: Fix the create option as flag
Prior to this commit, unexpectedly the option was not a flag:
-C, --no-create TEXT Do not attempt to create the database
So we would have had to pass along an extra boolean with the option.
Now it's simpler:
-c, --create / --no-create Attempt to create the database
Test Plan
tox
Migrated from D813 (view on Phabricator)