Tested manually but not unit test yet (bad bad Manu!). This happen when there were no write on the master between the last subscription and this one. Was happening frequently on my test cluster were writes are unfrequent after restarting the master or the slave. This was resulting in timeouts every 30 seconds until I finally written something on master. 

With this pull request, the first subscription is always backed by the store and switch to live transaction log replication if that subscription end without an error. The timeouts were preventing the switch to live replication mode.