vwout

To add more detail, this is the command used to reproduce: ``` # valgrind --leak-check=full --show-leak-kinds=all ./nyoci-prefix/bin/nyocictl -p 5684 -i id -P psk coaps://192.168.0.2 coaps://192.168.0.2> get /15001/65543 coaps://192.168.0.2> exit ```...

It looks like the leakage is caused by the SSL sessions. This btree is not cleaned up when the nyoci object closes, this in contrary to the transactions btree.