Remove wrapping transaction for account deletion

This uses a lot of memory for big accounts. Also it doesn't make much
sense to rollback everything when something fails, it's better to delete
everything we can.

lib/account_deleter.rb

@@ -25,8 +25,7 @@ class AccountDeleter
   end
 
   def perform!
-    ActiveRecord::Base.transaction do
-      #person
+    # close person
     delete_standard_person_associations
     remove_conversation_visibilities
     delete_contacts_of_me
@@ -36,7 +35,6 @@ class AccountDeleter
 
     mark_account_deletion_complete
   end
-  end
 
   # user deletion methods
   def close_user