Doc: Fix qthelp URL used in Remotecontrol example

Task-number: QTBUG-32877
Change-Id: Iecd50007e5790f0c938febe4e98e36275fe35a80
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Merge remote-tracking branch 'origin/release' into stable

Change-Id: Ida20e2ebeb6316e2c6916570ce2e166951af9ee2