fix(JingleSessionPC): fix crash/remove unused arg

Fixes crashed when null stream (muted) is being removed.

modules/xmpp/JingleSessionPC.js

  * NOTE: must be called within a work function being executed
  *  by the modification queue.
  */
-JingleSessionPC.prototype.removeStreamFromPeerConnection = function (stream, stopStream) {
-    let actualStream = stream && stream.getOriginalStream ? stream.getOriginalStream() : stream;
+JingleSessionPC.prototype.removeStreamFromPeerConnection = function (stream) {
+    let actualStream
+        = stream && stream.getOriginalStream
+            ? stream.getOriginalStream() : stream;
     if (!this.peerconnection) {
         return;
     }
     if (RTCBrowserType.getBrowserType() ===
             RTCBrowserType.RTC_BROWSER_FIREFOX) {
         this._handleFirefoxRemoveStream(actualStream);
-    } else if (stream) {
-        this.peerconnection.removeStream(actualStream, stopStream);
+    } else if (actualStream) {
+        this.peerconnection.removeStream(actualStream);
     }
 };
 
                 RTCBrowserType.RTC_BROWSER_FIREFOX) {
             this._handleFirefoxRemoveStream(stream);
         } else if (stream) {
-            this.removeStreamFromPeerConnection(stream, false);
+            this.removeStreamFromPeerConnection(stream);
         }
         let oldSdp = new SDP(this.peerconnection.localDescription.sdp);
         this._renegotiate()

modules/xmpp/TraceablePeerConnection.js

 
 import { getLogger } from "jitsi-meet-logger";
 const logger = getLogger(__filename);
-import RTC from '../RTC/RTC';
 import SdpConsistency from "./SdpConsistency.js";
 var RTCBrowserType = require("../RTC/RTCBrowserType.js");
 var XMPPEvents = require("../../service/xmpp/XMPPEvents");
     }
 };
 
-TraceablePeerConnection.prototype.removeStream = function (stream, stopStreams) {
+TraceablePeerConnection.prototype.removeStream = function (stream) {
     this.trace('removeStream', stream.id);
-    if (stopStreams) {
-        RTC.stopMediaStream(stream);
-    }
     // FF doesn't support this yet.
     if (this.peerconnection.removeStream) {
         this.peerconnection.removeStream(stream);