Not to render "top_group_label" when it's empty.
Not to render "top_group_label" when it's empty.

As below search response would lead to UI page with error message
"矮油，服务器好像开小差了", it's revised not to render "top_group_label"
when it's empty.

"top_group_label":[{"group_property":"Category"}]

izenecloud/sf1r-lite,pombredanne/sf1r-lite,izenecloud/sf1r-lite,izenecloud/sf1r-ad-delivery,pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-lite,izenecloud/sf1r-lite,pombredanne/sf1r-lite,pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-lite,izenecloud/sf1r-ad-delivery