replace double with triple equals

libtextsecure/message_receiver.js

@@ -855,7 +855,7 @@ MessageReceiver.prototype.extend({
   async innerHandleContentMessage(envelope, plaintext) {
     const content = textsecure.protobuf.Content.decode(plaintext);
 
-    if (envelope.type == textsecure.protobuf.Envelope.Type.FRIEND_REQUEST) {
+    if (envelope.type === textsecure.protobuf.Envelope.Type.FRIEND_REQUEST) {
       // only prompt friend request if there is no conversation yet
       let conversation;
       try {