refs #15452 [fid] ILSAuthenticator bug fix

module/fid/src/VuFind/Auth/ILSAuthenticator.php

@@ -42,8 +42,13 @@ class ILSAuthenticator
      */
     public function storedCatalogLogin()
     {
-        $user = $this->client->requestUserDetails();
-
+        try {
+            $user = $this->client->requestUserDetails();
+        } catch (ClientException $e) {
+            if ($e->getCode() == '401') {
+                return null;
+            } else throw $e;
+        }
         if (!$user) {
             return null;
         }