Fixed bug in rake task

lib/tasks/proposal_actions.rake

@@ -2,6 +2,8 @@ namespace :proposal_actions do
   desc 'Move link attribute to links collection'
   task migrate_links: :environment do
     ProposalDashboardAction.where.not(link: nil).each do |action|
+      next if action.link.blank?
+
       Link.create!(
         label: action.title,
         url: action.link,