switch from failure to anyhow

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

src/api2/config/datastore.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use failure::*;
+use anyhow::{bail, Error};
 use serde_json::Value;
 
 use proxmox::api::{api, ApiMethod, Router, RpcEnvironment, Permission};