Don't write windows paths in the config file

When it's read back in it's still treated as escape chars

Change-Id: I637c2b976860c2337c92d900fbfb39617d28d37b
Reviewed-on: http://review.couchbase.org/37089
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Tommie McAfee <tommie@couchbase.com>