test(emqx_trace_SUITE): fix failure due to new field

apps/emqx/test/emqx_trace_SUITE.erl

@@ -96,7 +96,8 @@ t_base_create_delete(_Config) ->
             start_at => Now,
             end_at => Now + 30 * 60,
             payload_encode => text,
-            extra => #{}
+            extra => #{},
+            formatter => plain
         }
     ],
     ?assertEqual(ExpectFormat, emqx_trace:format([TraceRec])),