Change hostname from '0.0.0.0' to '::' to enable dual stack support by default (#519)

0.0.0.0 only listens on legacy IP. changing to :: allows for use on any network - dual stacked, ipv6-only, or ipv4-only

Author: buraglio

server.js

@@ -31,7 +31,7 @@ function registerGlobalErrorHandlers() {
 registerGlobalErrorHandlers._registered = false;
 
 const dev = process.env.NODE_ENV !== 'production';
-const hostname = '0.0.0.0';
+const hostname = '::';
 const port = parseInt(process.env.PORT || '3000', 10);
 
 const app = next({ dev, hostname, port });