chat/gajim: Update to 1.3.1. Drop maintainership.

  New

  * Add a mobile phone indicator to the chat window
  * Rework HTTPUpload dialog
  * Add a "paste as quote" option to the message input

  Bug fixes

  * #8822 Fix memory leak when using spell checker
  * #9514 Fix jingle filetransfers not working in some circumstances
  * #9573 Dont leak DNS query when connecting over proxy
  * #9578 Determine Windows version more reliably
  * #9622 Fix an error while quitting Gajim
  * #9633 Fix an error while sending a file
  * #9637 Restore window size correctly on wayland
  * #9660 GPG Agent setting is ignored
  * #9645 Make zeroconf IPV6 compatible
  * Improve dark theme colors
  * Fix access to GnuPG keys
  * Use UUID4 item ids for pubsub posts
  * Dont send invalid show values
  * Windows: Dont override format region settings
  * Various smaller improvements

(nia)