Move two history entries mistake out of 7.9 section (#11013)

Move two history entries mistake out of 7.9 section (#11013)

Summary:
https://github.com/facebook/rocksdb/pull/10892 and https://github.com/facebook/rocksdb/pull/10955 mistakenly added two entries under sealed 7.9.history section. This PR fixes these two.

No need to update 7.9 branch (https://github.com/facebook/rocksdb/blob/7.9.fb/HISTORY.md) cuz it's cut before these two PRs landed

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11013

Reviewed By: cbi42

Differential Revision: D41666514

Pulled By: hx235

fbshipit-source-id: c4bc7a29ff663664bf0be1ba1c7eab4d00a61528