message: fix tree creation
diff: @@ -44,7 +44,7 @@ class MutableTree {
  }
  here = await entry.getTree();
  }
  - return this.insert(parts[0], object, filemode);
  + return here.insert(parts[0], object, filemode);
  }
  async write() {
  if (this.overlay.size === 0 && this.tree) {
  