Fix slow query test.

[CPWstatic]

The rebuild_index job is rate limited now. This makes the test has to wait for much time.

[bright-starry-sky]

The slow query test case passed. but another test failed. Let's fix them one by one.

newly failed:
test_delete_int_vid_one_vertex_all_tag

[CPWstatic]

close #2772

[critical27]

The slow query test case passed. but another test failed. Let's fix them one by one.

newly failed:
test_delete_int_vid_one_vertex_all_tag

There must be something wrong with the tck test framework when rebuild index speed is slower than expected. I guess it won't appear after #2795 merged.

[yixinglu]

The slow query test case passed. but another test failed. Let's fix them one by one.
newly failed:
test_delete_int_vid_one_vertex_all_tag

There must be something wrong with the tck test framework when rebuild index speed is slower than expected. I guess it won't appear after #2795 merged.

Even if index rebuilding slow down the whole tests, delete tag should be ok. I think we should find out the cause of the failure

[CPWstatic]

Fixed by #2795