diff --git a/source/conf.py b/source/conf.py
--- a/source/conf.py
+++ b/source/conf.py
@@ -327,8 +327,6 @@
 default_tags = []
 custom_tags = False
 
-tags = set()
-
 config_files = glob.glob('./*/conf.py')
 
 if os.path.exists('./conf.local.py'):
diff --git a/source/webmail-user-guide/roundcubemail-plugins-kolab b/source/webmail-user-guide/roundcubemail-plugins-kolab
--- a/source/webmail-user-guide/roundcubemail-plugins-kolab
+++ b/source/webmail-user-guide/roundcubemail-plugins-kolab
@@ -1 +1 @@
-Subproject commit c7eb3e729aa969178116a1c020b6f8543996c9b9
+Subproject commit 9e073403b8bfbfad079df21bb1357f05d9c0d290