Restore logging handler

[xThaid]

PR #573 accidentally broke logging by removing register_logging_handler from configure logging:

-    @pytest.fixture(autouse=True)
-    def configure_logging(self, fixture_sim_processes_to_add, register_logging_handler):
+    def configure_logging(self):

As a result, no logs were printed on the output.

I also found and removed an old print statement from test_log.py