Add comment that error files can now also be set in listen and backend sections

Author: darix

pillar.example

@@ -76,6 +76,7 @@ haproxy:
       - realm: 'Haproxy\ Statistics'
       - auth: 'admin1:AdMiN123'
 
+    # the same can be set in a per backend/listen as well
     errorfiles:
       400: /etc/haproxy/errors/400.http
       403: /etc/haproxy/errors/403.http