Add openapi link

Change-Id: Idcdf018d5d03c8b0a92c83f73679a318c6904624
diff --git a/kalamar.ids-mannheim.conf b/kalamar.ids-mannheim.conf
index 5f04c08..ad876e7 100644
--- a/kalamar.ids-mannheim.conf
+++ b/kalamar.ids-mannheim.conf
@@ -22,6 +22,7 @@
     experimental_proxy => 1,
     proxy_inactivity_timeout => 120,
     proxy_connect_timeout => 120,
+    openapi => 'openapi',
     Piwik => {
       ping_requests => 1,
       ping_site_id => 13