Make name of the identifier attribute set in config visible in the error message (#272)

Author: cicnavi

src/Services/AuthenticationService.php

@@ -105,7 +105,12 @@ public function getAuthenticateUser(
         if (!array_key_exists($this->userIdAttr, $claims) || !is_array($claims[$this->userIdAttr])) {
             $attr = implode(', ', array_keys($claims));
             throw new Error\Exception(
-                'Attribute `useridattr` doesn\'t exists in claims. Available attributes are: ' . $attr,
+                sprintf(
+                    'User identifier attribute `%s` does not exist in the user attribute state.' .
+                    ' Available attributes are: %s.',
+                    $this->userIdAttr,
+                    $attr,
+                ),
             );
         }