message: Simplify isPlainObject()
diff: @@ -69,11 +69,7 @@ export function merge(defaults, user) {
  }
  function isPlainObject(obj) {
  - if (typeof obj !== "object") {
  - return false;
  - }
  -
  - return obj.toString() === "[object Object]";
  + return typeof obj === "object" && obj.toString() === "[object Object]";
  }
  export function normalizePath(path) {
  