Executing test client: LOADING kvrocks is restoring the db from backup

[tisonkun]

Report: https://github.com/apache/incubator-kvrocks/runs/7026847364?check_suite_focus=true#step:10:713

[git-hulk]

I will follow up this issue, it should be caused by forbidding to get role when restoring
the data.

[PragmaTwice]

There is another fail with same exception: https://github.com/apache/incubator-kvrocks/runs/7085774273?check_suite_focus=true
But I feel that the root cause of this error and the above error may be different, because the execution path seems to be different.

[git-hulk]

Looks caused by this line: replication.tcl#L196, need to wait for restoring. Will fix it later.