Merge branch 'nginx' into 'master'

Don't enable IPv4 *only* on nginx.

I came across this issue when initially setting up gitlab and fixed it locally. Today, helping someone else set up their own instance, I came across this issue again:

The sample nginx configuration files disable IPv6 by default, making the server inaccesible unless the remote node has native IPv4. IPv4->IPv6 transition mechanisms don't help if the server have proper IPv6 DNS records in-place, which was the case for both of my servers.

This branch enables IPv4 and IPv6 by default. Older servers with no external IPv6 connectivity will not fail since they'll have a local-link IPv6 address to bind to anyway.

See merge request !231

lib/support/nginx/gitlab

@@ -33,7 +33,8 @@ upstream gitlab {
 
 ## Normal HTTP host
 server {
-  listen *:80 default_server;
+  listen 0.0.0.0:80 default_server;
+  listen [::]:80 default_server;
   server_name YOUR_SERVER_FQDN; ## Replace this with something like gitlab.example.com
   server_tokens off; ## Don't show the nginx version number, a security best practice
   root /home/git/gitlab/public;

lib/support/nginx/gitlab-ssl

@@ -39,7 +39,8 @@ upstream gitlab {
 
 ## Normal HTTP host
 server {
-  listen *:80 default_server;
+  listen 0.0.0.0:80;
+  listen [::]:80 default_server;
   server_name YOUR_SERVER_FQDN; ## Replace this with something like gitlab.example.com
   server_tokens off; ## Don't show the nginx version number, a security best practice
 
@@ -50,7 +51,8 @@ server {
 
 ## HTTPS host
 server {
-  listen 443 ssl;
+  listen 0.0.0.0:443 ssl;
+  listen [::]:443 ssl default_server;
   server_name YOUR_SERVER_FQDN; ## Replace this with something like gitlab.example.com
   server_tokens off;
   root /home/git/gitlab/public;