Bump src193 patchlevel up to 1.9.3-p392 [FIXED]

This Ruby patch takes care of some of the recent vulnerabilities (JSON parsing and XML denial of service).

More info here:
http://www.ruby-lang.org/en/news/2013/02/22/ruby-1-9-3-p392-is-released/

(This one has the correct patchlevel)