add qtwebengine 1.0 custom branch to submodule updater

Change-Id: I0aca04e3f6af45f3d568ff2bdde9b75210c1c31e
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>