fix(UI): Show the correct message on NO_DATA_FROM_SOURCE GUM errors

modules/UI/UI.js

     = "dialog.cameraNotFoundError";
 JITSI_TRACK_ERROR_TO_MESSAGE_KEY_MAP.camera[TrackErrors.CONSTRAINT_FAILED]
     = "dialog.cameraConstraintFailedError";
+JITSI_TRACK_ERROR_TO_MESSAGE_KEY_MAP.camera[TrackErrors.NO_DATA_FROM_SOURCE]
+    = "dialog.cameraNotSendingData";
 JITSI_TRACK_ERROR_TO_MESSAGE_KEY_MAP.microphone[TrackErrors.GENERAL]
     = "dialog.micUnknownError";
 JITSI_TRACK_ERROR_TO_MESSAGE_KEY_MAP.microphone[TrackErrors.PERMISSION_DENIED]
     = "dialog.micNotFoundError";
 JITSI_TRACK_ERROR_TO_MESSAGE_KEY_MAP.microphone[TrackErrors.CONSTRAINT_FAILED]
     = "dialog.micConstraintFailedError";
+JITSI_TRACK_ERROR_TO_MESSAGE_KEY_MAP.microphone[TrackErrors.NO_DATA_FROM_SOURCE]
+    = "dialog.micNotSendingData";
 
 /**
  * Prompt user for nickname.