hooks: made the callback host configurable.

- This allows easier docker container seperation

configs/production.ini

@@ -520,6 +520,9 @@ vcs.scm_app_implementation = http
 ## Push/Pull operations hooks protocol, available options are:
 ## `http` - use http-rpc backend (default)
 vcs.hooks.protocol = http
+## Host on which this instance is listening for hooks. If vcsserver is in other location
+## this should be adjusted.
+vcs.hooks.host = 127.0.0.1
 
 vcs.server.log_level = info
 ## Start VCSServer with this instance as a subprocess, usefull for development