let terbium talk to gmetad on nickel

the dbtree tool (http://noc.wikimedia.org/dbtree/)
has been moved from fenari over to terbium, and it needs
to talk to the XML port of gmetad (ganglia @ nickel)
to fetch information about db servers to build the tree

terbium needs to become a trusted host or gmetad doesn't
talk to it and "failure reading ganglia" and dbtree is broken

Change-Id: I1dbdbb4de4b27d502319d841b808a5bfa700bab3
RT: 8365
Merge "let terbium talk to gmetad on nickel" into production