add changelog entry for #2396

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## 3.2.2-solc-0.7 (unreleased)
+ * Resolve warnings introduced by Solidity 0.7.4. ([#2396](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2396))
+
 ## 3.2.1-solc-0.7 (2020-09-15)
 
 * `ERC777`: Remove a warning about function state visibility in Solidity 0.7. ([#2327](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2327))