Allow hyper client to make http connections

When using the DefaultServiceAccount the request is over http, using
https there is not supported.  Since all the used URLs are hardcoded
there is no risk of accidentally not using https when needed.

Author: Floris Bruynooghe

src/lib.rs

@@ -100,7 +100,7 @@ async fn get_authentication_manager(
     let https = HttpsConnectorBuilder::new().with_native_roots();
 
     let client =
-        Client::builder().build::<_, hyper::Body>(https.https_only().enable_http2().build());
+        Client::builder().build::<_, hyper::Body>(https.https_or_http().enable_http2().build());
 
     let custom = match credential_path {
         Some(path) => CustomServiceAccount::from_file(path).await,