use new proxmox-async crate

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>

src/api2/reader/mod.rs

@@ -289,7 +289,7 @@ fn download_chunk(
 
         env.debug(format!("download chunk {:?}", path));
 
-        let data = pbs_runtime::block_in_place(|| std::fs::read(path))
+        let data = proxmox_async::runtime::block_in_place(|| std::fs::read(path))
             .map_err(move |err| http_err!(BAD_REQUEST, "reading file {:?} failed: {}", path2, err))?;
 
         let body = Body::from(data);