Update to libp2p 0.12 (#3408)

substrate/core/network/src/protocol/event.rs

@@ -17,21 +17,21 @@
 //! Network event types. These are are not the part of the protocol, but rather
 //! events that happen on the network like DHT get/put results received.
 
-use libp2p::multihash::Multihash;
+use libp2p::kad::record::Key;
 
 /// Events generated by DHT as a response to get_value and put_value requests.
 pub enum DhtEvent {
 	/// The value was found.
-	ValueFound(Vec<(Multihash, Vec<u8>)>),
+	ValueFound(Vec<(Key, Vec<u8>)>),
 
 	/// The requested record has not been found in the DHT.
-	ValueNotFound(Multihash),
+	ValueNotFound(Key),
 
 	/// The record has been successfully inserted into the DHT.
-	ValuePut(Multihash),
+	ValuePut(Key),
 
 	/// An error has occured while putting a record into the DHT.
-	ValuePutFailed(Multihash),
+	ValuePutFailed(Key),
 }
 
 /// Type for events generated by networking layer.