MB-100: use ip addresses instead of domain names in xperf ini files

Change-Id: I0e729988c375eeac3cf8b10f4f3f803fbf8da3ed
Reviewed-on: http://review.couchbase.org/24692
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>
Tested-by: Pavel Paulau <pavel.paulau@gmail.com>