When a review request has multiple configurations for the same

integration, manual runs behave incorrectly. They check for a matching

configuration, and may get a configuration that doesn't actually match

the one triggering the run. In this case, some other configuration may

end up running.
Review Board 5.0.3 adds support for tracking configurations along with

StatusUpdates and passing them to the signal handler for manual runs.

This change takes advantage of that to use the stored configuration.
Since prior versions of 5.0.x can upgrade to this release of

rbintegrations, this change also backports some of the logic, manually

storing the configuration association and looking it up if not provided

to the signal handler.

Unit tests pass.
Manually tested conditions with and without the new logic in both

Review Board and in rbintegrations.
This change will be tested in production by a customer affected by this

issue.