(Rust) Memory leak
Related:
(Rust) Zeroize memory
https://github.com/paritytech/substrate/issues/3085
ここで：
https://github.com/libp2p/rust-libp2p/blob/2fd941122a6c589501ad1c04b0f091f1337f5f49/protocols/kad/src/behaviour.rs#L1399
対処：
https://github.com/libp2p/rust-libp2p/pull/1217