update nginx config as it will need to know the IPs it can listen on to avoid conflict with the fast server

resource/nginx.cfg

@@ -1,13 +1,13 @@
 server {
-    listen [::]:80;
+    listen YOUR_IPV4_IP:80;
-    listen 0.0.0.0:80;
+    listen [YOUR_IPV6_IP]:80;
     server_name postal.yourdomain.com;
     return 301 https://$host$request_uri;
 }
 
 server {
-    listen [::]:443 ssl;
+    listen YOUR_IPV4_IP:443 ssl;
-    listen 0.0.0.0:443 ssl;
+    listen [YOUR_IPV6_IP]:443 ssl;
     root /opt/postal/app/public;
     server_name postal.yourdomain.com;
     ssl_certificate      ssl/postal.crt;