Java: Don't free locals after detaching thread.
Java: Don't free locals after detaching thread.

We use a smart pointer to hold local java variables, and it was getting
destructed after DetachCurrentThread() was called, causing a JVM crash.

wpilibsuite/ntcore,robotdotnet/ntcore,wpilibsuite/ntcore,333fred/ntcore,robotdotnet/ntcore,wpilibsuite/ntcore,robotdotnet/ntcore,robotdotnet/ntcore,333fred/ntcore,333fred/ntcore,wpilibsuite/ntcore,333fred/ntcore