This fixes an issue where this script fails with the default Dash shell
on Ubuntu (where "$0" is "-bash" and it is parsed as an option).

Change-Id: I6fec2a7b4e8eee68b5f11101783d7dff7d07f712
Reviewed-by: Donald Carr <donald.carr@theqtcompany.com>
Reviewed-by: Risto Avila <risto.avila@theqtcompany.com>
Reviewed-by: Samuli Piippo <samuli.piippo@theqtcompany.com>