msi: Dont crash on installation of services without component KeyPath

[Hans Leidekker]

On Wed, 2014-02-19 at 17:57 +0900, Aric Stewart wrote:
> Well the image path in the component is optional and looking at the documentation
> for CreateServiceW lpBinaryPathName is also optional.  So it seemed correct.
> 
> If you feel like we should just exit then that is acceptable as well. 

What happens on Windows?