Catch empty WEBMAIL and WEBDAV address

core/nginx/conf/nginx.conf

@@ -43,8 +43,12 @@ http {
       # Variables for proxifying
       set $admin {{ ADMIN_ADDRESS }};
       set $antispam {{ ANTISPAM_ADDRESS }};
+      {% if WEBMAIL_ADDRESS %}
       set $webmail {{ WEBMAIL_ADDRESS }};
+      {% endif %}
+      {% if WEBDAV_ADDRESS %}
       set $webdav {{ WEBDAV_ADDRESS }};
+      {% endif %}
 
       # Always listen over HTTP
       listen 80;