Fix a logging call to provide all format parameters.

Review Request #9818 — Created March 22, 2018 and submitted — Latest diff uploaded

Information

Djblets
release-1.0.x
ae06985...

Reviewers

An error log message when attempting to unpack static media wasn't
passing enough arguments to a format string. This change fixes that up.

While I was here I noticed that we had some calls that were using a
named logger and some that were using logging. I've changed them all
to used the named logger.

Ran unit tests.