mod_http_oauth2: Make note about handling repeated RFC 6749 states > If an authorization code is used more than once, the authorization > server MUST deny the request and SHOULD revoke (when possible) all > tokens previously issued based on that authorization code. We should follow the SHOULD. The MUST is already covered by removing the code state from the cache.

# Introduction

This module sends a [version query][xep0092] to clients when they
connect, and logs the response, allowing statistics of client usage to
be recorded.

Note that since this is per connection, there will be a bias towards
mobile clients on bad connections.

## Example

    info    Running Running Swift version 4.0