message: fix multi-select test case bug detection in IE9
diff: @@ -6,10 +6,11 @@ import { looseEqual } from 'shared/util'
  function hasMultiSelectBug () {
  var s = document.createElement('select')
  s.setAttribute('multiple', '')
  - s.innerHTML = '<option>1</option>'
  - s.options[0].selected = true
  - s.options[0].selected = false
  - return s.options[0].selected !== false
  + var o = document.createElement('option')
  + s.appendChild(o)
  + o.selected = true
  + o.selected = false
  + return o.selected !== false
  }
  /**
  