Don't flush notify msgs from msg queue

src/lager_util.erl

@@ -556,41 +556,19 @@ check_hwm(Shaper = #lager_shaper{lasttime = Last, dropped = Drop}) ->
     case Last of
         {M, S, N} ->
             %% still in same second, but have exceeded the high water mark
-            NewDrops = discard_messages(Now, Shaper#lager_shaper.filter, 0),
             Timer = case erlang:read_timer(Shaper#lager_shaper.timer) of
                         false ->
                             erlang:send_after(trunc((1000000 - N)/1000), self(), {shaper_expired, Shaper#lager_shaper.id});
                         _ ->
                             Shaper#lager_shaper.timer
                     end,
-            {false, 0, Shaper#lager_shaper{dropped=Drop+NewDrops, timer=Timer}};
+            {false, 0, Shaper#lager_shaper{dropped=Drop+1, timer=Timer}};
         _ ->
             erlang:cancel_timer(Shaper#lager_shaper.timer),
             %% different second, reset all counters and allow it
             {true, Drop, Shaper#lager_shaper{dropped = 0, mps=1, lasttime = Now}}
     end.
 
-discard_messages(Second, Filter, Count) ->
-    {M, S, _} = os:timestamp(),
-    case Second of
-        {M, S, _} ->
-            receive
-                %% we only discard gen_event notifications, because
-                %% otherwise we might discard gen_event internal
-                %% messages, such as trapped EXITs
-                {notify, Event} ->
-                    NewCount = case Filter(Event) of
-                                   false -> Count+1;
-                                   true -> Count
-                               end,
-                    discard_messages(Second, Filter, NewCount)
-            after 0 ->
-                    Count
-            end;
-        _ ->
-            Count
-    end.
-
 %% @private Build an atom for the gen_event process based on a sink name.
 %% For historical reasons, the default gen_event process for lager itself is named
 %% `lager_event'. For all other sinks, it is SinkName++`_lager_event'