fix(binding-coap): include IPv6 when no address specified

This is just a strawman hotfix to start the work on fixing IPv6 support for the CoAP server. Untested on IPv4-only machines and not considering the `net.ipv6.bindv6only` sysctl parameter (depends on the expectation of the user).

Author: mkovatsc

packages/binding-coap/src/coap-server.ts

@@ -83,7 +83,7 @@ export default class CoapServer implements ProtocolServer {
 
     constructor(config?: CoapServerConfig) {
         this.port = config?.port ?? 5683;
-        this.address = config?.address;
+        this.address = config?.address ?? "::";
 
         // WoT-specific content formats
         registerFormat(ContentSerdes.JSON_LD, 2100);