The cmake wizard proposes also ninja if ninja support is available

Ninja must be in PATH, but it is only called once, so it doesn't hurt.

Task-number: QTCREATORBUG-7720
Change-Id: If3c9c7ae55e6990fa16b031fc2998a8d8d9ed17a
Reviewed-by: Daniel Teske <daniel.teske@digia.com>