message: fixed checkbox material for vue
diff: <template>
  <form :class="css.checkbox.root">
  - <div v-for="(item, index) in question.visibleChoices" :class="css.radiogroup.item" :style="{width: colWidth, 'margin-right': question.colCount === 0 ? '5px': '0px'}">
  + <div v-for="(item, index) in question.visibleChoices" :class="css.checkbox.item" :style="{width: colWidth, 'margin-right': question.colCount === 0 ? '5px': '0px'}">
  <label :class="css.checkbox.item">
  <input type="checkbox" :name="question.name" :value="item.value" v-model="value" :id="question.inputId + '_' + item.value" :disabled="question.isReadOnly" />
  <span class="checkbox-material"><span class="check"></span></span>
  