Unbreak endless invocation loop with "info" pages
QWebEngine was handling info: urls as something to invoke an external handler for. Which... is khelpcenter itself.
So instead of opening the page, there would be an endless invocation loop (don't try at home, myself only could fix that by killing the dbus-daemon (perhaps unregistering khelpcenter as scheme handler might also work, but killing was fine and quicker in my developer setup :) ).
Backport candidate.
Edited by Friedrich W. H. Kossebau