do not drain the channel because there is no channel, duh

Fixes https://github.com/cosmos/cosmos-sdk/issues/1045

p2p/conn/connection.go

@@ -545,9 +545,7 @@ FOR_LOOP:
 // not goroutine-safe
 func (c *MConnection) stopPongTimer() {
 	if c.pongTimer != nil {
-		if !c.pongTimer.Stop() {
-			<-c.pongTimer.C
-		}
+		_ = c.pongTimer.Stop()
 		c.pongTimer = nil
 	}
 }

p2p/conn/connection_test.go

@@ -6,9 +6,11 @@ import (
 	"testing"
 	"time"
 
+	"github.com/fortytw2/leaktest"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"github.com/tendermint/go-amino"
+
+	amino "github.com/tendermint/go-amino"
 	"github.com/tendermint/tmlibs/log"
 )
 
@@ -242,7 +244,11 @@ func TestMConnectionMultiplePings(t *testing.T) {
 }
 
 func TestMConnectionPingPongs(t *testing.T) {
+	// check that we are not leaking any go-routines
+	defer leaktest.CheckTimeout(t, 10*time.Second)()
+
 	server, client := net.Pipe()
+
 	defer server.Close()
 	defer client.Close()