message: Moved changelog entry to correct section.
diff: ### Internals
  -* Lorem ipsum.
  +* Fix an assert that prevented `Group::commit()` from discarding history from a
  + Realm file opened in nonshared mode (via `Group::open()`, as opposed to
  + `SharedGroup::open()`).
  ----------------------------------------------
  * Disabled a sleep in debug mode that was impairing external tests.
  PR [#2651](https://github.com/realm/realm-core/pull/2651).
  -* Fix an assert that prevented `Group::commit()` from discarding history from a
  - Realm file opened in nonshared mode (via `Group::open()`, as opposed to
  - `SharedGroup::open()`).
  ----------------------------------------------
  