inhibit: don't abort when directaccess is not enabled
When directaccess is not enabled, we should just print a warning and not set up
inhibit. We don't need to abort in that case. Example: if the user is running
hg showconfig, we don't want to crash as the command is unrelated to inhibit.
inhibit: add missing locking in wrapper for obsmarker creation
The develwarning for transaction without lock rightfully pointed out to this
issue. Before this patch we were not locking in the transaction for obsmarker
creation and therefore showing the warnings.