Unable to bind a TCP server stream to IPv6 Any Address

[b2ag]

Describe the bug
I'm unable to configure Snapcast/Snapserver to create a TCP server stream bound to the IPv6 Any Address.

Steps to Reproduce

1. Add a stream with tcp://[::]:12345?name=test&mode=server
2. Fail
3. Add a stream with tcp://:::12345?name=test&mode=server
4. Fail again
5. Try without port tcp://::?name=test&mode=server
6. Fail
7. Try without port but with brackets tcp://[::]?name=test&mode=server
8. Fail again
9. Try with IPv4 tcp://0.0.0.0:12345?name=test&mode=server
10. And it just works

Environment details

• OS: NixOS unstable
• Snapcast version 0.27.0
• Unmodified/default Nix package

(non-debug) Log

Feb 07 12:37:06 eric snapserver[129616]: Version 0.27.0
Feb 07 12:37:06 eric snapserver[129616]: Adding stream: tcp://[::]:1706?name=kyle&mode=server
Feb 07 12:37:06 eric snapserver[129616]: Adding stream: pipe:///run/snapserver/mpd@eric?name=mpd@eric
Feb 07 12:37:06 eric snapserver[129616]: Settings file: "/var/lib/snapserver/server.json"
Feb 07 12:37:06 eric snapserver[129616]: daemonizing
Feb 07 12:37:06 eric snapserver[129655]: daemon started
Feb 07 12:37:06 eric snapserver[129655]: Using HTTP host name: eric
Feb 07 12:37:06 eric snapserver[129655]: Failed to create client: An unexpected D-Bus error occurred
Feb 07 12:37:06 eric snapserver[129655]: PcmStream: kyle, sampleFormat: 48000:16:2
Feb 07 12:37:06 eric snapserver[129655]: TcpStream host: [::]:1706, port: 4953, is server: 1
Feb 07 12:37:06 eric snapserver[129655]: Server::start: Invalid argument [system:22]
Feb 07 12:37:06 eric snapserver[129655]: Exception: Invalid argument [system:22]
Feb 07 12:37:06 eric snapserver[129655]: Snapserver terminated.
...
Feb 07 12:43:24 eric snapserver[131481]: Version 0.27.0
Feb 07 12:43:24 eric snapserver[131481]: Adding stream: tcp://:::1706?name=kyle&mode=server
Feb 07 12:43:24 eric snapserver[131481]: Adding stream: pipe:///run/snapserver/mpd@eric?name=mpd@eric
Feb 07 12:43:24 eric snapserver[131481]: Settings file: "/var/lib/snapserver/server.json"
Feb 07 12:43:24 eric snapserver[131481]: daemonizing
Feb 07 12:43:24 eric snapserver[131513]: daemon started
Feb 07 12:43:24 eric snapserver[131513]: Using HTTP host name: eric
Feb 07 12:43:24 eric snapserver[131513]: Failed to create client: An unexpected D-Bus error occurred
Feb 07 12:43:24 eric snapserver[131513]: PcmStream: kyle, sampleFormat: 48000:16:2
Feb 07 12:43:24 eric snapserver[131513]: TcpStream host: :::1706, port: 4953, is server: 1
Feb 07 12:43:24 eric snapserver[131513]: Server::start: Invalid argument [system:22]
Feb 07 12:43:24 eric snapserver[131513]: Exception: Invalid argument [system:22]
Feb 07 12:43:24 eric snapserver[131513]: Snapserver terminated.
...
Other two configurations also result in Server::start: Invalid argument [system:22]