Fix typo in CHANGELOG (OpenZeppelin#3191)

Author: GitHubPang

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unreleased
 
- * `AccessControl`: add a virtual `_checkRole(bytes32)` function that can be overriden to alter the `onlyRole` modifier behavior. ([#3137](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3137))
+ * `AccessControl`: add a virtual `_checkRole(bytes32)` function that can be overridden to alter the `onlyRole` modifier behavior. ([#3137](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3137))
  * `EnumerableMap`: add new `AddressToUintMap` map type. ([#3150](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3150))
  * `ERC1155`: Add a `_afterTokenTransfer` hook for improved extensibility. ([#3166](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3166))