Relayd "cannot load certificates" when using 2 'listen' statements in a relay

[Unicorn]

Hello,

I am just figuring out relayd and am trying to make it listen both on
my ipv4 and ipv6 address. I have specified them with these macros:
```
$ext_ipv4 = "blah"
$ext_ipv6 = "expandedblah"
```


Then I have this relay with the two listen statements, to listen on
ipv4 and ipv6:
```
relay "proxy_secure" {
    listen on $ext_ipv4 port 443 tls
    listen on $ext_ipv6 port 443 tls

    protocol "https"

    forward to <blah1> port 1001
    forward to <blah2> port 1002
}
```


Finally, this is the relevant part of the "https" protocol:
```
http protocol "https" {
    ...
    tls keypair "firstdomain.tld"
    tls keypair "seconddomain.tld"
}
```


With both listen statements, 'relayd -n' throws this error:

"/etc/relayd.conf:58: cannot load certificates for relay
proxy_secure4:443"

Removing either of the 'listen' statements resolves this issue, but
that would mean listening only on ipv4 OR ipv6. How could I solve this
issue? Am I missing something obvious? The manpage makes me believe
that having two 'listen' statements in a single relay is not an issue
per se, so why is relayd unhappy with this specific configuration?

I'd be very thankful for your guidance. :)

Best,
Unicorn