Pass Host/X-Forwarded-For everywhere

It hasn't mattered much to have these so far, but
it's probably a good idea to have them.

roles/matrix-nginx-proxy/templates/nginx-conf.d/matrix-riot-web.conf.j2

@@ -50,6 +50,7 @@ server {
 			proxy_pass http://localhost:8765;
 		{% endif %}
 
+		proxy_set_header Host $host;
 		proxy_set_header X-Forwarded-For $remote_addr;
     }
 }

roles/matrix-nginx-proxy/templates/nginx-conf.d/matrix-synapse.conf.j2

@@ -57,6 +57,9 @@ server {
 			{# Generic configuration for use outside of our container setup #}
 			proxy_pass http://{{ matrix_nginx_proxy_proxy_matrix_corporal_api_addr_sans_container }};
 		{% endif %}
+
+		proxy_set_header Host $host;
+		proxy_set_header X-Forwarded-For $remote_addr;
 	}
 	{% endif %}
 
@@ -109,6 +112,7 @@ server {
 			proxy_pass http://{{ matrix_nginx_proxy_proxy_matrix_client_api_addr_sans_container }};
 		{% endif %}
 
+		proxy_set_header Host $host;
 		proxy_set_header X-Forwarded-For $remote_addr;
 
 		client_body_buffer_size 25M;