message: Add missing links to pull requests for two entries in the CHANGELOG.
diff: ### Bugfixes
  * Fix a hang in LIKE queries that could occur if the pattern required
  - backtracking.
  + backtracking. PR [#2477](https://github.com/realm/realm-core/pull/2477).
  * Bug fixed in `GroupWriter::write_group()` where the maximum size of the top
  array was calculated incorrectly. This bug had the potential to cause
  - corruption in Realm files.
  + corruption in Realm files. PR [#2480](https://github.com/realm/realm-core/pull/2480).
  ### Breaking changes
  