Code review comment for lp:~gary/launchpad/opstats-nodb

This branch fixes the errors shown in the recent buildbot run for db-devel (https://lpbuildbot.canonical.com/builders/db_lp/builds/313/steps/shell_7/logs/summary).

The comment additions hopefully explain the purpose of the changes.

To test the formerly failing tests, use this command:

./bin/test -vv -ttest_other_request_uses_LaunchpadDatabasePolicy -ttest_read_only_mode_uses_ReadOnlyLaunchpadDatabasePolicy -twebapp-publication.txt

To test the pertinent test that stub added for this code, run this command:

./bin/test -vvtxx-opstats.txt

Thank you

Gary