First attempt

src/controllers/openid_controller.rs

@@ -272,7 +272,7 @@ pub async fn token(
             }
 
             // Basic authentication
-            (None, None, Some(v)) => {
+            (_, None, Some(v)) => {
                 let token = match v.to_str().unwrap_or_default().strip_prefix("Basic ") {
                     None => {
                         return Ok(error_response(
@@ -309,7 +309,7 @@ pub async fn token(
                 return Ok(error_response(
                     &query,
                     "invalid_request",
-                    "Authentication method unknown!",
+                    "Client authentication method on token endpoint unsupported!",
                 ));
             }
         };