FIX creating sample data dci-cargo sampel A

Hi,

I was going through the samples and discovered that the sample data of dci-cargo was not created at startup, which resulted in a null pointer exception.

This fixes the problem.

By the way, I'm not able to run the forum, rental, and dci-cargo sample B examples. They all give errors on assembling/activating the application. I didn't manage to fix these errors.

Cheers,

Stijn