Don't emit event if log is empty

lib/exw3.ex

@@ -352,12 +352,14 @@ defmodule ExW3 do
 	  loop(Map.put(state, filter_id, %{pid: pid, signature: event_signature}))
 	{:event, filter_id, logs} ->
 	  filter_attributes = Map.get(state, filter_id)
+	  unless logs == [] do
 	    Enum.each(logs, fn log ->
 	      data = Map.get(log, "data")
 	      new_data = ExW3.decode_event(data, filter_attributes[:signature])
 	      new_log = Map.put(log, :data, new_data)
 	      send filter_attributes[:pid], {:event, {filter_id, new_log}}
 	    end)
+	  end
 	  loop(state)
       end
     end