Cleanup fails when nested classes are used

[Clashsoft]

Example code:

public class HelloWorld {
  <T> HelloWorld() {
    class Foo {
      T get() { return null; }
    }
  }
}

Shows disassembled code:

Unable to cleanup.

I believe the error stems from this line:

https://github.com/jkeam/javabytes/blob/74caae85b18fdd1ca959041da7abd925a2e10644/app/models/Disassembler.scala#L148

It fails if there is more than one .class file, because the non-empty folder cannot be deleted.