Fix Ofbiz to run on latest JDK.

[Jeff Prickett]

I mentioned this in the user list a week and a half ago, but I am going to
start working on making the build possible for JDK 13. There was already an
open issue for JDK 11 and I looked at that. It looks like the one issue I
am seeing with JDK 13 is the same thing.

I look forward to working with you.

Thanks.