fix optional type

Author: naman9271

modules/RTC/TraceablePeerConnection.ts

@@ -73,7 +73,7 @@ interface ITouchToneRequest {
 export interface ITPCOptions {
     audioQuality: IAudioQuality;
     capScreenshareBitrate: boolean;
-    codecSettings: ICodecSettings;
+    codecSettings?: ICodecSettings;
     disableRtx: boolean;
     disableSimulcast?: boolean;
     enableInsertableStreams?: boolean;