Adding a short hint to *:80 for default listen address on nginx example config

Based on posting https://github.com/gitlabhq/gitlabhq/issues/3384#issuecomment-15457287 I was able to solved an issue here. Pointing out *:80 might could prevent others for struggeling here

lib/support/nginx/gitlab

@@ -7,7 +7,7 @@ upstream gitlab {
 }
 
 server {
-  listen YOUR_SERVER_IP:80 default_server;         # e.g., listen 192.168.1.1:80;
+  listen YOUR_SERVER_IP:80 default_server;         # e.g., listen 192.168.1.1:80; In most cases *:80 is a good idea
   server_name YOUR_SERVER_FQDN;     # e.g., server_name source.example.com;
   root /home/git/gitlab/public;