sysutils/appjail: Update to 3.1.0

ChangeLog: https://github.com/DtxdF/AppJail/releases/tag/v3.1.0

• Added: {nullfs|<pseudofs>}:reverse feature.
• Improved: AppJail image: Add Imagetype. Improve Slogan.
• Improved: creation of a bridge (A lock file is used to ensure that the bridge is not attempted to be created by two or more processes at the same time.).
• Fixed: bottleneck in repeat (sleep(1) command is now started after a command failure instead of executing on the first try. This ensures that the command exits as quickly as possible instead of waiting for the sleep(1) time and the command time.).

PR: 276355
Reported by: DtxdF@disroot.org (maintainer)