changelog: note breaking change in the 0.33.6 release (#5077)

CHANGELOG.md

@@ -58,7 +58,11 @@ program](https://hackerone.com/tendermint).
 ### SECURITY:
 
 - [consensus] Do not allow signatures for a wrong block in commits (@ebuchman)
-- [consensus] Verify all the signatures during block execution (@melekes)
+- [consensus] Verify all the signatures during block execution (@melekes) 
+
+**Please note that the fix for the False Witness issue renames the `VerifyCommitTrusting`
+function to `VerifyCommitLightTrusting`. If you were relying on the light client, you may
+need to update your code.**
 
 ## v0.33.5