Refactor address-to-hex-string conversion in `_checkRole` function (#3509)

Signed-off-by: Pascal Marco Caversaccio <pascal.caversaccio@hotmail.ch>
Co-authored-by: Francisco <frangio.1@gmail.com>

contracts/access/AccessControl.sol

@@ -110,7 +110,7 @@ abstract contract AccessControl is Context, IAccessControl, ERC165 {
                 string(
                     abi.encodePacked(
                         "AccessControl: account ",
-                        Strings.toHexString(uint160(account), 20),
+                        Strings.toHexString(account),
                         " is missing role ",
                         Strings.toHexString(uint256(role), 32)
                     )