Update whatsapp vendor and fix a panic (#1209)

* Fix another whatsapp panic

* Update whatsapp vendor

vendor/github.com/Rhymen/go-whatsapp/read.go

@@ -5,13 +5,14 @@ import (
 	"crypto/sha256"
 	"encoding/json"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+
 	"github.com/Rhymen/go-whatsapp/binary"
 	"github.com/Rhymen/go-whatsapp/crypto/cbc"
 	"github.com/gorilla/websocket"
 	"github.com/pkg/errors"
-	"io"
-	"io/ioutil"
-	"strings"
 )
 
 func (wac *Conn) readPump() {
@@ -27,7 +28,9 @@ func (wac *Conn) readPump() {
 	for {
 		readerFound := make(chan struct{})
 		go func() {
-			msgType, reader, readErr = wac.ws.conn.NextReader()
+			if wac.ws != nil {
+				msgType, reader, readErr = wac.ws.conn.NextReader()
+			}
 			close(readerFound)
 		}()
 		select {