mod_http_muc_log: Fix exception on lack of trailing slash in room path
A request to /room leads to the match call returning nil which in turn
calls nodeprep(nil). In Prosody 0.11.x this does nothing and simply
returns the nil, while in 0.12 it is an error.
Now it redirects to the calendar view at /room/ - even for non-existant
rooms.
Discovered at a deployment with http_paths = { muc_log = "/" } and
requests to /robots.txt and similar, which now result in a uses redirect
before returning 404.
2c07bcf56a36d6e74dc0f5422e89bd61f4d31239 0.8-diverge
1656d4fd71d07aa3a52da89d4daf7723a555e7dd last-google-code-commit