Cannot configure OpenVPN on a DHCP interface that has not received an IP address
If the interface that an OpenVPN server or client is being configured on uses DHCP and has not yet received an IP address, then the OpenVPN Server/Client validation complains "An IPv4 protocol was selected, but the selected interface has no IPv4 address."
Similar if a gateway group is chosen that contains 1 or more gateways that use DHCP, and none of those gateways have yet got an IP address.
The same sort of thing happens when using an IPv6 protocol and interface or gateway group that uses DHCP6 and has not yet received an IPv6 address.
And I know this has been discussed before, so there may be an issue already about this, but I can't find it.
It is annoying specially when setting up a system that is not yet online. It would be nice to allow this case through, assuming that if the interface/gateway group uses DHCP/DHCP6 then it will in future get an IPv4/IPv6 address.
Fix #7031 Allow interfaces that use DHCP for OpenVPN
even though the interface (or gateway group) has not yet actually
received an IP address.
This is useful when setting up a new system that is currently offline.