Minor typo in example

[cavemanloverboy]

The delete_file.rs example mistakenly returns "failed to request storage account deletion" when failing to request to delete a file

#[tokio::main]
async fn main() {
    //load keypair from file
    let keypair = read_keypair_file(KEYPAIR_PATH).expect("failed to load keypair at path");
    let storage_account_key =
        Pubkey::from_str("B7Qk2omAvchkePhzHubCVQuVpZHcieqPQCwFxeeBZGuT").unwrap();

    //create shdw drive client
    let solana_rpc = RpcClient::new("https://ssc-dao.genesysgo.net");
    let shdw_drive_client = ShadowDriveClient::new(keypair, solana_rpc);

    let url = String::from(
        "https://shdw-drive.genesysgo.net/B7Qk2omAvchkePhzHubCVQuVpZHcieqPQCwFxeeBZGuT/hey.txt",
    );

    //delete file
    let delete_file_response = shdw_drive_client
        .delete_file(&storage_account_key, url)
        .await
        .expect("failed to request storage account deletion");

    println!("Delete file complete {:?}", delete_file_response);
}