(3.4) last_vote.js should make assertCurrentTerm exception safe

last_vote.js will restart nodes and then check their terms with assertCurrentTerm. After a restart, we need to wait until we can connect to a node again before trying to check the term, so we should be wrapping this in an exception safe retry, as done in this ticket: SERVER-27083. The change in SERVER-27083 to last_vote.js was never backported, so we should make the change on 3.4.