fixed bug when selecting multiple elements from different streams

app/services/data/load_element_data.rb

@@ -59,7 +59,8 @@ class LoadElementData
     req_streams.each do |stream|
       adapter = DbAdapter.new(stream.db.url)
       data_service = LoadStreamData.new(adapter)
-      data_service.run(stream, @start_time, @end_time,elements.to_a)
+      stream_elements = elements.select{|e| e.db_stream_id==stream.id}.to_a
+      data_service.run(stream, @start_time, @end_time,stream_elements)
 
       if data_service.success?
         combined_data.concat(data_service.data)