Close WebRTC video correctly

packages/rocketchat-webrtc/webrtc.js

@@ -32,6 +32,8 @@ webrtc = {
 
 		if (webrtc.pc) {
 			if (webrtc.pc.signalingState != 'closed') {
+				webrtc.pc.getLocalStreams().forEach(function(stream) {stream.stop()})
+				webrtc.pc.getRemoteStreams().forEach(function(stream) {stream.stop()})
 				webrtc.pc.close();
 			webrtc.pc = undefined;
 			webrtc.mode = 0;