fix typo (#942)

* fix typo

Author: gfr10598

cmd/etl_worker/app-batch.yaml

@@ -44,7 +44,7 @@ env_variables:
   RELEASE_TAG: ${TRAVIS_TAG}
   COMMIT_HASH: ${TRAVIS_COMMIT}
 
-  PROMETHEUSX_LISTEN_ADDRESS: ':9090' . # Must match one of the forwarded_ports above.
+  PROMETHEUSX_LISTEN_ADDRESS: ':9090' # Must match one of the forwarded_ports above.
   BATCH_SERVICE: 'true'   # Allow instances to discover they are BATCH instances.
   MAX_WORKERS: 20
   BIGQUERY_PROJECT: '${INJECTED_PROJECT}'  # Overrides GCLOUD_PROJECT