style(rubocop): fix all safe auto correctable offenses

app/jobs/prune_suppression_lists_job.rb

@@ -1,8 +1,10 @@
 class PruneSuppressionListsJob < Postal::Job
+
   def perform
     Server.all.each do |s|
       log "Pruning suppression lists for server #{s.id}"
       s.message_db.suppression_list.prune
     end
   end
+
 end