fix(electron): Check for unsuported gDM

Wrong check for unsupported getDisplayMedia when starting screen sharing will cause the app to never fallback to getUserMedia flow. This breaks screen sharing for all old electron clients that do not support getDisplayMedia.

modules/RTC/ScreenObtainer.js

 
                 logger.warn('getDisplayMedia error', JSON.stringify(constraints), JSON.stringify(errorDetails));
 
-                if (errorDetails.code === DOMException.NOT_SUPPORTED_ERR) {
+                if (errorDetails.errorCode === DOMException.NOT_SUPPORTED_ERR) {
                     // This error is thrown when an Electron client has not set a permissions handler.
                     errorCallback(new JitsiTrackError(JitsiTrackErrors.SCREENSHARING_NOT_SUPPORTED_ERROR));
                 } else if (errorDetails.errorMsg?.indexOf('denied by system') !== -1) {