Remove unnecessary sleep

ethereum/p2p/src/test/java/tech/pegasys/pantheon/ethereum/p2p/discovery/internal/PeerDiscoveryControllerTest.java

@@ -423,8 +423,6 @@ public void peerSeenTwice() throws InterruptedException {
     neighborsPacket = Packet.create(PacketType.NEIGHBORS, neighbors, keyPairs.get(1));
     controller.onMessage(neighborsPacket, peers.get(1));
 
-    // Wait for 1 second and ensure that only 1 PING was ever sent to peer[2].
-    Thread.sleep(1000);
     verify(outboundMessageHandler, times(1))
         .send(eq(peers.get(2)), matchPacketOfType(PacketType.PING));
   }