Remove unused spec file

The rpm file won't work now that we've moved over to cmake
anyway (cleanup)

Change-Id: I18f67c3d3c9367bcaa964653fe02ba8242bc1e3f
Reviewed-on: http://review.couchbase.org/35444
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>