message: refactor: check is function for fallback slots
diff: @@ -24,13 +24,11 @@ export function renderSlot (
  }
  nodes =
  scopedSlotFn(props) ||
  - (fallbackRender &&
  - (Array.isArray(fallbackRender) ? fallbackRender : fallbackRender()))
  + (typeof fallbackRender === 'function' ? fallbackRender() : fallbackRender)
  } else {
  nodes =
  this.$slots[name] ||
  - (fallbackRender &&
  - (Array.isArray(fallbackRender) ? fallbackRender : fallbackRender()))
  + (typeof fallbackRender === 'function' ? fallbackRender() : fallbackRender)
  }
  const target = props && props.slot
  