If Last Number Redial is used to redial, ensure that we do not wait
for further digits. This was possible if the number that was last
dialed is a prefix of another possible dialplan match. Since all we
did is copy the number into the extension buffer, if other matches
are now possible, there would thus be a timeout before the call went
through. We now complete redialed calls immediaetly in all cases.
Resolves: #1483
f86812d4f0