Fix: Don't send agent disable event command twice

The session daemon sends a "disable event" command to agents for each
event, enabled or not, on session destroy. This had no adverse effect
of the Java agent since it suffered from an unrelated bug which ignored
any refcount decrementation.

This fix bumps the command version to "1" to indicate that this behavior
is fixed on the session daemon's end.

Fixes #884

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>