lock: allows global lock to be used from main app (PROJQUAY-788) (#745)

GlobalLock had a dependency on app, which would cause a circular
dependency if imported from the main app. Workaround this by requiring
to pass the configuration to the GlobalLock instead (this is done by a
classmethod, due to the use of Redlock's factory). This means before
the use of GlobalLock, "configure" will need to be called once, per process.

workers/blobuploadcleanupworker/blobuploadcleanupworker.py

@@ -86,5 +86,6 @@ def create_gunicorn_worker():
 
 if __name__ == "__main__":
     logging.config.fileConfig(logfile_path(debug=False), disable_existing_loggers=False)
+    GlobalLock.configure(app.config)
     worker = BlobUploadCleanupWorker()
     worker.start()