Java-AIInterface: actually look for the class-name! (thanks to playerO1) [fix]

This was most likely a c&p error.
It looks like code from the releaseSkirmishAIClass() function
that was adjusted a bit, but badly so.
Merge pull request #136 from hoijui/javaAIInterfaceFix

Java-AIInterface: actually look for the class-name! (thanks to playerO1)...