Update Qt icon used in the example

Change-Id: Ic5cecb60b2dc600cbbe7d7e6ab31a505c8ba1b26
Reviewed-by: Christian Stromme <christian.stromme@digia.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Merge remote-tracking branch 'origin/5.4' into dev

Change-Id: I427a8b159440fa8a01dfb2267215cb83b2524a79