relay: Automatically Enable an IPv6 ORPort
This commit makes it that if the ORPort is set with a single port, it will bind to both global listen IPv4 and IPv6 addresses.
To pin an "ORPort " to be IPv4 or IPv6, the IPv4Only/IPv6Only flags are honored thus this will only bind on IPv6 for that port value:
ORPort 9050 IPv6Only Results in: [::]:9050
ORPort 9051 IPv4Only Results in: [0.0.0.0]:9051
Attempting to configure an explicit IPv4 address with IPv6Only flag is an error and vice versa.
Closes #33246 (closed)
Signed-off-by: David Goulet dgoulet@torproject.org