Add set directives for proxies to keep from crashing if upstream is down

Author: ddshd

backend/templates/_location.conf

@@ -6,7 +6,12 @@
     proxy_set_header X-Forwarded-Proto  $scheme;
     proxy_set_header X-Forwarded-For    $remote_addr;
     proxy_set_header X-Real-IP		$remote_addr;
-    proxy_pass       {{ forward_scheme }}://{{ forward_host }}:{{ forward_port }}{{ forward_path }};
+
+    set $proxy_forward_scheme {{ forward_scheme }};
+    set $proxy_server         "{{ forward_host }}";
+    set $proxy_port           {{ forward_port }};
+
+    proxy_pass       $proxy_forward_scheme://$proxy_server:$proxy_port{{ forward_path }};
 
     {% include "_access.conf" %}
     {% include "_assets.conf" %}