monitor-image-loaded doesn't work, when we use a slot.

[pareshchouhan]

Monitor-image-loaded doesn't work with slots.

    <stack :column-min-width="320" ref="stack" :gutter-width="22" :gutter-height="22" monitor-images-loaded style="transition: transform 300ms" @scroll.native.passive="onUserScrollBottom">
      <stack-item v-for="(item, i) in items" :key="i" style="transition: transform 300ms">
        <slot name="item" :page="page" :item="item" :index="i" />
      </stack-item>
    </stack>