Update proxy URL to use PUMA defaults (0.0.0.0:9292) 

as apache's mod_proxy doesn't support sockets.
see: http://httpd.apache.org/docs/2.2/mod/mod_proxy.html
original commit: https://github.com/dmb-dz/gitlab-recipes/commit/de05cf29ae62e78bd4ac983ba0894ffc23fee6a5