Eliminate the consistency error on create group (ready for review)

So previously, we changed the read state in modify_state to also have consistency quorum.  However, when a group is created, it not only reads the state, it has to call `obey_launch_config`, which then reads the launch config, and that was probably what was causing the consistency bug, since that read is consistency ONE.

However, we can just eliminate that read, since on create, we already have the launch config that the user passed to us.

The read of the launch config must be preserved, though, since update config also calls `obey_launch_config`, and it does not have easy access to a launch config.