Fix typo in ERC721.sol (#3127)

contracts/token/ERC721/ERC721.sol

@@ -100,7 +100,7 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
     /**
      * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
      * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
-     * by default, can be overriden in child contracts.
+     * by default, can be overridden in child contracts.
      */
     function _baseURI() internal view virtual returns (string memory) {
         return "";