MB-12913: Use automake 1.11.1 RPM for CentOS-65

CentOS 6.5 already has automake-1.11.1 available as a pre-packaged
RPM, so no need to compile ourselves from source.

Change-Id: I19a12664bf6f81dce000345842984709d09cd919
Reviewed-on: http://review.couchbase.org/44467
Tested-by: Dave Rigby <daver@couchbase.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>