Add a log statement to know when the poller processes a paused module build

We encountered an issue where start_next_batch_build was called twice on a
module build and it caused the module build to fail because Brew failed
one of the components since it was submitted twice. This will help us narrow
down the issue if it happens again.

module_build_service/scheduler/producer.py

@@ -231,6 +231,7 @@ class MBSProducer(PollingProducer):
         log.warning('process_open_component_builds is not yet implemented...')
 
     def process_paused_module_builds(self, config, session):
+        log.info('Looking for paused module builds in the build state')
         if module_build_service.utils.at_concurrent_component_threshold(
                 config, session):
             log.debug('Will not attempt to start paused module builds due to '
@@ -255,6 +256,7 @@ class MBSProducer(PollingProducer):
             # repo-regen.
             if (not module_build.current_batch(koji.BUILD_STATES['BUILDING']) and
                not module_build.new_repo_task_id):
+                log.info('  Processing the paused module build %r', module_build)
                 # Initialize the builder...
                 builder = GenericBuilder.create_from_module(
                     session, module_build, config)