mod_http_oauth2: Tweak method of centering the UI The percentage here was relative to the viewport width, which on some very wide screens may put the UI slightly outside of the view, requiring scrolling to see. By using a unit relative to the height of the viewport, this is avoided and should work better. But no guarantees, it's still possible to resize the browser or adjust font sizes so that the UI goes out of view.

# 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