NOJIRA-OAuth-Tests: Fixes OAuth test failures

Change is twofold:

1. A number of small changes to allow the checkstyle build to resume
2. The reason for test failures was that the test classes were somewhat tied to the mocked logger object of the class under test, expecting particular a message to be logged. Decided to remove the static logger from tests and verification of error messages logged, since that's extra coupling between tests and classes.