openvpn: try to "solve" get_failover_interface() issues
openvpn: try to "solve" get_failover_interface() issues

This seems to be a cosmetic cleanup.  get_failover_interface()
is used incorrectly but then merely seems to be used to look
up IPv4 connectivity to make a "smart" decision about resync
duties.

A few annoying and disabled line removals while here.

opnsense/core,opnsense/core,opnsense/core,opnsense/core,opnsense/core,opnsense/core