Fix call to migrate.

The redis-rb client takes the additional info as an options hash, not as additional arguments.

I'm using redis-rb v3.0.7, which takes only two arguments, see https://github.com/redis/redis-rb/blob/master/lib/redis.rb#L399
I couldn't find the code that it ever took 5 arguments, so I think this code in redis-trib.rb should have never worked.