jni.hh: Fix JNI handle conversion functions
jni.hh: Fix JNI handle conversion functions

I don't know what I have been smoking when I implemented those... The
world breaks as soon as one of the affected classes have their first
virtual method and the layout changes.

Signed-off-by: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@iki.fi>

penberg/hornet,penberg/hornet,penberg/hornet,penberg/hornet