Readd the nick to the payloads of offer/answer

The RTCSessionDescription removes custom payload attributes in it's toJSON
method. The one value we set is the nick, so we need to toJSON and toObject
the description and add the nick to the payload again.
{@see https://developer.mozilla.org/en-US/docs/Web/API/RTCSessionDescription/toJSON}

Signed-off-by: Joas Schilling <coding@schilljs.com>

js/signaling.js

@@ -573,9 +573,18 @@
 		} else if(data.type === 'offer') {
 			console.log("OFFER", data);
 		}
+
+		// The RTCSessionDescription removes custom payload attributes in it's toJSON
+		// method. The one value we set is the nick, so we need to toJSON and toObject
+		// the description and add the nick to the payload again.
+		// {@see https://developer.mozilla.org/en-US/docs/Web/API/RTCSessionDescription/toJSON}
+		var tempString =  JSON.stringify(data);
+		var tempData = JSON.parse(tempString);
+		tempData.payload.nick = data.payload.nick;
+
 		this.spreedArrayConnection.push({
 			ev: "message",
-			fn: JSON.stringify(data),
+			fn: JSON.stringify(tempData),
 			sessionId: this.sessionId
 		});
 	};