Upgrade to Antora UI 0.4.18.

Author: mp911de

antora-playbook.yml

@@ -33,7 +33,7 @@ urls:
   redirect_facility: httpd
 ui:
   bundle:
-    url: https://github.com/spring-io/antora-ui-spring/releases/download/v0.4.16/ui-bundle.zip
+    url: https://github.com/spring-io/antora-ui-spring/releases/download/v0.4.18/ui-bundle.zip
     snapshot: true
 runtime:
   log: