Wicket usually redirects a lot. It uses the redirect after post pattern to solve the double submit problem.
Suppose the Wicket application is running in a servlet container (like Tomcat or Jetty).
Apache HTTPD connects to the client using HTTPS and that HTTPS is terminated at the HTTPD server before it is forwarded tot the servlet container.
Therefore the Header directive in a configuration file for Apache HTTPD is typical in Apache HTTPD for a wicket application running in a servlet container behind Apache:
It looks like this is the logical place for manipulation of the URL since this is also the place where SSL is terminated (HTTPS stops at Apache HTTPD and HTTP is then forwarded to the servlet container).
This is useful if all of your application must be served over HTTPS.
Wicket has some other facilities for HTTPS but that is useful only if some but not all of your pages must be served over HTTPS.