mod_lua: Add a fixups hook that checks if the original request is intended

for LuaMapHandler. This fixes a bug where FallbackResource invalidates the 
LuaMapHandler directive in certain cases by changing the URI before the map 
handler code executes [Daniel Gruno].

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1577145 13f79535-47bb-0310-9956-ffa450edef68