Fixes nagios overwrite of apache configuration

The apache puppet module was on a version that deleted
configurations by default, this patch upgrades to the
latest version of the upstream module which has a feature
that allows to keep the configurations; also modifies the
nagios and horizon templates to use this feature,
bringing a decoupling and clean up of some extra code
from the templates.

Change-Id: I4032d138a404111aed7368c7b8d2593df7ae16d1
Fixes: rhbz#1054498
(cherry picked from commit b0b2449a73c4ec3443fc3750f974b5e85571acce)