beta: memcached multiwrite to pmtpa and eqiad

I started creating instances for the beta cluster on eqiad. I got two
new memcached servers:

 deployment-memc02.eqiad.wmflabs 10.68.16.14
 deployment-memc03.eqiad.wmflabs 10.68.16.15

I would like MediaWiki to write to both datacenters. Hopefully this
configuration would work.

Change-Id: If84c2513d4b1ecc1c13bc5ebe565211730654ce7