I think the last device we sold was in 2011 and I am not aware
if anyone has used it for the last couple of years. Remove it
to lower the complexity of the builds.
This addresses the following warning of OpenVPN:
WARNING: No server certificate verification method has been enabled. See http://openvpn.net/howto.html#mitm for more info.
This way I just need to install sysmocom-openvpn-config and copy
a matching key to the device for the VPN config. The configuration
file is marked as a CONFFILE, this means that modifications to it
will not be lost during upgrade.