Increase replication timeout to 5 minutes

For very large projects, when Gerrit is under load, it can take
longer than 60 seconds for the submit action to be processed and the
associated commit to replicate to its local mirror, causing Zuul to
think the change did not merge and resetting any remaining changes
in that dependent queue. Increase this to 5 minutes, since the
impact from these "phantom gate resets" is more significant than any
potential increase in merge wait time.

Change-Id: If57d5ed2720707c1ec3a3477dd229f042789fa1f