Fix filtered search tests

Review Request #9164 — Created Aug. 31, 2017 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
519f02e...

Reviewers

The filter argument to the search form was renamed to model_filter
during review and I missed a few instances of it, causing some test
failures. In addition, the SearchTests class did not disable search
again once it finished. Both of these issues have been addressed.

Ran unit tests.