Testconfig: Force OSX binary package stage to succeed

Current CI nodes are lacking disk space to successfully build
this stage.

Change-Id: Ie56bbc6c60cdf6e9fcc5d289f1053ed80c882cc7
Reviewed-by: Jani Heikkinen <jani.heikkinen@theqtcompany.com>
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>