FIX: Don't send extra_data when exporting results to JSON

The extra data is needed to render avatars and user metadata when rendering results in the browser,
we can skip this data for JSON exports to reduce bloat

plugin.rb

@@ -1115,9 +1115,12 @@ SQL
               default_limit: DataExplorer::QUERY_RESULT_MAX_LIMIT
             }
             json[:explain] = result[:explain] if opts[:explain]
-            ext = DataExplorer.add_extra_data(pg_result)
-            json[:colrender] = ext[1]
-            json[:relations] = ext[0]
+
+            if !params[:download]
+              ext = DataExplorer.add_extra_data(pg_result)
+              json[:colrender] = ext[1]
+              json[:relations] = ext[0]
+            end
 
             json[:rows] = pg_result.values