Merge branch 'sh-release-8.3.1' into 'master'

Release 8.3.1 to fix version numbering

See merge request gitlab-org/gitlab-shell!241

CHANGELOG

+v8.3.1
+  - No changes (version tag correction)
+
 v8.3.0
   - Add custom action (e.g. proxying SSH push) support
 

VERSION

-8.3.0
+8.3.1