Merge pull request #4309 from vespa-engine/toregge/expect-reported-er…

…ror-for-bad-streaming-mode-grouping

Expect reported error when grouping on nonexisting field

tests/search/multipledoctypes/multipledoctypes.rb

@@ -81,7 +81,7 @@ def test_one_search_cluster
     res_both = search(query + '&format=json')
     assert_equal(5, res_one.hitcount)
     # Errors might cause incomplete grouping results
-    assert_nil(res_both.errorlist) if is_streaming
+    assert_not_nil(res_both.errorlist)
     assert_equal(13, res_both.hitcount)
     group_one = extract_group(res_one)
     group_both = extract_group(res_both)