Fixed learning object importer empty verification

Signed-off-by: Israel Sant'Anna <ibsa14@inf.ufpr.br>

lib/tasks/import/learning_objects.rake

@@ -31,10 +31,6 @@ namespace :import do
         # Terminate loop if there are no more items to import
         break if dspace_items.empty?
 
-        dspace_items.select! do |i|
-          i.parent_collection.id == DspaceService::BD_INT_OBJETOS_COLLECTION
-        end
-        next if dspace_items.empty?
         # continue if receive an error string
         if dspace_items.is_a? String
           logger.warn "Received a string instead of items: #{dspace_items}"
@@ -44,6 +40,10 @@ namespace :import do
         # Increment offset, to get new items on next iteration
         offset += limit
 
+        dspace_items.select! do |i|
+          i.parent_collection.id == DspaceService::BD_INT_OBJETOS_COLLECTION
+        end
+        next if dspace_items.empty?
         # Iterates through items
         # Verifies if item is already on repository
         # Initializes new LearningObjects