nginx: Set X-Forwarded-For in common proxy configuration.

Previously we sometimes set it to $proxy_add_x_forwarded_for and other
times to $remote_addr, but according to

http://wiki.nginx.org/HttpProxyModule#.24proxy_add_x_forwarded_for

$proxy_add_x_forwarded_for handles this for us -- it will be
$remote_addr if there was no X-Forwarded-For header anyway.

(imported from commit 67dc52250e3e7751b1bf375d1a71d0272475435c)

puppet/zulip/files/nginx/zulip-include/app

@@ -19,7 +19,6 @@ location ~ /json/get_events|/json/events|/api/v1/events {
     include /etc/nginx/zulip-include/proxy_longpolling;
 
     proxy_set_header X-Real-IP       $remote_addr;
-    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 }
 
 # Send sockjs requests to Tornado

puppet/zulip/files/nginx/zulip-include/location-sockjs

@@ -4,4 +4,3 @@ include /etc/nginx/zulip-include/proxy_longpolling;
 proxy_set_header Upgrade         $http_upgrade;
 proxy_set_header Connection      $connection_upgrade;
 proxy_set_header X-Real-IP       $remote_addr;
-proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

puppet/zulip/files/nginx/zulip-include/proxy

@@ -1,4 +1,5 @@
 proxy_http_version 1.1;
 proxy_set_header Host $host;
+proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 proxy_next_upstream off;
 proxy_redirect off;

puppet/zulip_internal/files/nginx/sites-available/loadbalancer

@@ -31,7 +31,6 @@ server {
     location ~ /json/get_events|/json/events|/api/v1/events {
         proxy_pass https://staging/;
         include /etc/nginx/zulip-include/proxy_longpolling;
-        proxy_set_header X-Forwarded-For $remote_addr;
     }
 }
 
@@ -56,7 +55,6 @@ server {
     location ~ /json/get_events|/json/events|/api/v1/events {
         proxy_pass https://prod/;
         include /etc/nginx/zulip-include/proxy_longpolling;
-        proxy_set_header X-Forwarded-For $remote_addr;
     }
 }
 
@@ -80,7 +78,6 @@ server {
     location ~ /json/get_events|/json/events|/api/v1/events {
         proxy_pass https://prod/;
         include /etc/nginx/zulip-include/proxy_longpolling;
-        proxy_set_header X-Forwarded-For $remote_addr;
     }
 }
 
@@ -105,7 +102,6 @@ server {
     location ~ /json/get_events|/json/events|/api/v1/events {
         proxy_pass https://prod/;
         include /etc/nginx/zulip-include/proxy_longpolling;
-        proxy_set_header X-Forwarded-For $remote_addr;
     }
 }
 
@@ -129,7 +125,6 @@ server {
     location ~ /json/get_events|/json/events|/api/v1/events {
         proxy_pass https://prod/;
         include /etc/nginx/zulip-include/proxy_longpolling;
-        proxy_set_header X-Forwarded-For $remote_addr;
     }
 }
 
@@ -154,7 +149,6 @@ server {
     location ~ /json/get_events|/json/events|/api/v1/events {
         proxy_pass https://prod/;
         include /etc/nginx/zulip-include/proxy_longpolling;
-        proxy_set_header X-Forwarded-For $remote_addr;
     }
 }
 

puppet/zulip_internal/files/nginx/zulip-include/loadbalancer

@@ -1,2 +1 @@
 include /etc/nginx/zulip-include/proxy;
-proxy_set_header X-Forwarded-For $remote_addr;