Remove duplicate arguments in 'zato create cluster'

[dsuch]

The 'zato create cluster' command uses 'broker_host' and 'broker_port' twice - this should be removed.

This is trivial to fix - just remove two options superfluously appended to opts in zato.cli.create_cluster.Create.

zato create cluster [-h] [--store-log] [--verbose] [--store-config]
      [--postgresql_schema POSTGRESQL_SCHEMA] [--odb_password 
      ODB_PASSWORD] [--tech_account_password TECH_ACCOUNT_PASSWORD]
      odb_type odb_host odb_port odb_user odb_db_name
      lb_host lb_port lb_agent_port 
      **broker_host** **broker_port** cluster_name
      broker_host broker_port tech_account_name