These were fun to hunt down. The jcon and the conn are allocated off
of ld, so the free order is unspecified and if conn is freed before
conn then the finish_jcon destructor uses conn after free.
[ Edit: split commit, modified to use a destructor directly on jcon,
which is more robust than relying on it only being freed via conn --RR ]
Signed-off-by: Christian Decker <decker.christian@gmail.com>
3564263e12