Issue #3315394 by John Franklin: Fix a warning when creating a new client configuration.

src/Plugin/OpenIDConnectClient/OpenIDConnectLoginGovClient.php

@@ -85,7 +85,7 @@ class OpenIDConnectLoginGovClient extends OpenIDConnectClientBase {
   public function defaultConfiguration(): array {
     return [
       'client_id' => '',
-      'acr_level' => 'ial/1',
+      'acr_level' => ['ial/1'],
       'require_piv' => FALSE,
       'force_reauth' => FALSE,
       'sandbox_mode' => TRUE,