message: fix(observer): invoke getters on initial observation if setter defined
diff: @@ -147,10 +147,10 @@ export function defineReactive (
  // cater for pre-defined getter/setters
  const getter = property && property.get
  - if (!getter && arguments.length === 2) {
  + const setter = property && property.set
  + if ((!getter || setter) && arguments.length === 2) {
  val = obj[key]
  }
  - const setter = property && property.set
  let childOb = !shallow && observe(val)
  Object.defineProperty(obj, key, {
  