mod_http_muc_log: Fix redirect bug If you somehow went to /muc_log/room/yyyy-mm-dd/something it would send you in a redirect loop that continuously added path components until the path can't be parsed anymore. This should ensure that /muc_log/room/date/ is simply 404'd

This module blocks configured queries that change server state.

E.g. to make vCard storage read-only:

``` lua
readonly_stores = {
	vcard = { "vcard-temp", "vCard" };
}
```