message: [mint][docker] fix typo in server
  Closes:
  Approved by: sherry-x
diff: @@ -24,7 +24,7 @@ def create_client():
  ac_port = os.environ['AC_PORT']
  url = "http://{}:{}".format(ac_host, ac_port)
  waypoint = open("/opt/libra/etc/waypoint.txt", "r").readline()
  - chain_id = os.environ('CHAIN_ID')
  + chain_id = os.environ['CHAIN_ID']
  print("Connecting to ac on: {}".format(url))
  cmd = "/opt/libra/bin/cli --url {} -m {} --waypoint {} --chain-id {}".format(
  