Internal services should be available over VPN connections

A user connected over VPN to OpenVPN on FreedomBox should be able to use services that are available on internal networks only.

• Test that this works, if not, fix it
• Modify the internal zone warning shown in Service pages (e.g. Privoxy) to mention that the service will work over VPN

Internal only apps

• Privoxy
• Tor Socks
• Avahi
• Shadowsocks
• Bind
• I2P Proxy
• Samba
• MiniDLNA