extend nginx timeout in dev_setup

Change-Id: Ic00e1a682cf66fcedc7fdeba0f0172f447d3179c

dev_setup/cookbooks/nginx/templates/default/ubuntu-nginx.conf.erb

@@ -57,8 +57,8 @@ http {
                 proxy_set_header                X-Forwarded_Proto http;
                 proxy_redirect                  off;
                 proxy_connect_timeout           10;
-                proxy_send_timeout              30;
-                proxy_read_timeout              30;
+                proxy_send_timeout              300;
+                proxy_read_timeout              300;
                 proxy_pass                      http://vcap_router;
         }
     }