QtIFW

Fix 5d9fa6ed0eb13a63aed63fe5642db3e1b3936b8b.

If we install a component with essential tag, remember to
restart to. It's not sufficient to do this in write
un-installer, as this will only be called if the ui shuts down.

Change-Id: I1188254d94cb83c2cdffd5cfa04e4da0b2e9ecdb
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>