Release: Ruby Server update 2.3.12.6

[Belinda Frick]

The only change is that the time difference between the Servers
and Supervisors is now updated every 5 minutes.

This should help with problems with call durations appearing
incorrectly on the Supervisors. Version 2.3.12.2 of the
Supervisor is best to use with this Server, but it can be
used with any version without problems.