New TurnKey WireGuard version (18.1)

v18.1 rebuild - includes latest Debian & TurnKey packages.
Bugfix add_client confconsole plug-in - untracked bug. [Anton Pyrogovskyi ]
Configuration console (confconsole) - v2.1.6:
- Bugfix broken DNS-01 Let's Encrypt challenge - closes #1876 & #1895. Fixed in v2.1.5 - already included in some appliances.
- Let's Encrypt/Dehydrated - bugfix cron failure - closes #1962.
- General dehydrated-wrapper code cleanup - now passes shellcheck.
Reduce log noise by creating ntpsec log dir - closes #1952.