mod_http_oauth2: Do not enforce PKCE on Device and OOB flows PKCE does not appear to be used with the Device flow. I have found no mention of any interaction between those standards. Since no data is delivered via redirects in these cases, PKCE may not serve any purpose. This is mostly a problem because we reuse the authorization code to implement the Device and OOB flows.

This module helps reduces power usage of inactive mobile clients while
another client is actively used. E.g. in the case of chatting on a
desktop computer, instantly pushing messages to a phone in someones
pocket is not the best use of radio time.

Works with [mod_csi_simple][doc:modules:mod_csi_simple] which is
included with Prosody since 0.11