www/opengist: Update to 1.12.2

Changes since 1.12.1:

v1.12.2

Added

• Search all fields (#622).
• Display a form to create an Opengist account coming from a OAuth provider (#623).
• Rebuild search index in admin options (#647).

Fixed

• Clean file path names on file creation (#624).
• Support UTF-8 on gist download (#625).
• CSRF skipper only for GET *.js request (#627).
• Async-loaded gist embed scripts (#630).
• Make gists username/urls case insensitive in URLS (#641).
• Improve code search and index tests (#663).
• Translation strings (#659).
• Gitea avatar URL on OAuth (#674).

Admins of Opengist instances may want to run "Rebuild search index"
in the admin panel.