mod_http_oauth2: Fix removal of consumed authorization codes Fixes mod_http_oauth2.lua:34: bad argument #2 to 'difftime' (number expected, got nil) The extra preceding argument to :set stored the client-id#code as a value instead of clearing the key, and then later in the periodic cleanup timer this string would be indexed, producing a nil and a traceback

Prosody 0.12 added an API allowing modules to report their status. This
module allows reading these statuses via HTTP for use in monitoring.

```
$ curl http://prosody.localhost:5280/status
{
   "example.com" : {
      "c2s" : {
         "message" : "Loaded",
         "type" : "core"
      }
   }
}
```