mod_http_oauth2: Tweak fallback error text Since the oauth error is more like the error condition, a symbolic error code, not the most human-friendly. Many error cases do have human-readable error descriptions that should be fine on their own, or changed to be. As a fallback, capitalize the error name.

This module discards typing notifications sent to a bare host JID,
preventing error replies to be sent. These errors are harmless but can
be annoying sometimes if your client shows them prominently.