message: Fix undefined toString
diff: @@ -94,7 +94,7 @@ export function makeEventHandler(client: Historian): EventListener {
  try {
  state.target = elemPath(target);
  } catch (err) {
  - state.target = `<${err.toString()}>`;
  + state.target = `<${String(err)}>`;
  }
  client.pushHistory(state);
  