XDCR updater could run into invalid state transition

When replication starts/restarts, and gets an error in the start up process, e.g., because of failure to retrieve start seqnos, it sometimes reports an error "Can't move update state from 0 to 1".

There are two issues:
1. The error message is incorrect. It should have been "from 0 to 2".
2. The error should not have been raised. It indicates a problem with state management in pipeline updater.