follower holds stale ip for other peers

[Besroy]

Currently the only opportunity for followers to update peers' addresses is during the pre-vote process. If a member is elected as follower, append logs and want to fetch data from leader on data channel, since the pre-vote will not happen during log appending, there was no chance to update the addresses. As a result, data fetching will continually fail. We need to implement a mechanism to handle such errors on the data channel.

More details in issue27

[szmyd]

Is this fixed int he PR above? If so can we close this issue?