setting ca_name for wikitech.w.o cert

The CA name isn't set for anyplace in the config for the
wikitech.wikimedia.org certificate declaration (that i can see), which
results in an improper certificate chain being created.  with no
delcared ca_name, it defaults to our internal chain.

Change-Id: Id49c1bd3df10621b10a91ac7ca0ce8ec45f728ae