icinga - add monitor group for misc codfw servers

This group needs to be added once, then all servers
with cluster=misc, such as install2001 for now, should
show up in it.

Gives us a nice link into Icinga to watch just codfw,
like for pmtpa and eqiad.

Change-Id: If5353439c04446696284491a61905ed9675ebdc5
Merge "icinga - add monitor group for misc codfw servers" into production