Fix error message in case of server error

Change-Id: I72528fea917f91d16b3fee8cb4c47282b9b08556
diff --git a/t/plugin/auth-oauth.t b/t/plugin/auth-oauth.t
index 7db935f..33ffafa 100644
--- a/t/plugin/auth-oauth.t
+++ b/t/plugin/auth-oauth.t
@@ -236,6 +236,11 @@
   ->element_exists_not('p.hint')
   ;
 
+# Query with error
+$t->get_ok('/?q=error')
+  ->status_is(400)
+  ->text_is('#notifications .notify-error','500: Internal Server Error')
+;
 
 # Logout
 $t->get_ok('/user/logout')