Use the default color when migrating labels

db/migrate/20140729152420_migrate_taggable_labels.rb

@@ -16,7 +16,7 @@ class MigrateTaggableLabels < ActiveRecord::Migration
   def create_label_from_tagging(tagging)
     target = tagging.taggable
     label_name = tagging.tag.name.tr('?&,', '')
-    label = target.project.labels.find_or_create_by(title: label_name)
+    label = target.project.labels.find_or_create_by(title: label_name, color: Label::DEFAULT_COLOR)
 
     if label.valid? && LabelLink.create(label: label, target: target)
       print '.'