Ensure djblets.log.tests runs correctly when run standalone

Review Request #9503 — Created Jan. 20, 2018 and submitted — Latest diff uploaded

Information

Djblets
release-1.0.x
8214a1a...

Reviewers

Running ./tests/runtests.py djblets.log.tests would fail due to the
djblets.log.middleware module (which replaces the default debug cursor
wrapper with our own that includes stack traces) was not being imported.
We now just import the module to ensure the code is run.

Ran unit tests, both standalone and entire suite.