Fix old migrations failing because of new version of `strong_migrations` (#10904)

db/migrate/20171005102658_create_account_moderation_notes.rb

@@ -8,6 +8,6 @@ class CreateAccountModerationNotes < ActiveRecord::Migration[5.1]
       t.timestamps
     end
 
-    add_foreign_key :account_moderation_notes, :accounts, column: :target_account_id
+    safety_assured { add_foreign_key :account_moderation_notes, :accounts, column: :target_account_id }
   end
 end

db/migrate/20171010023049_add_foreign_key_to_account_moderation_notes.rb

 class AddForeignKeyToAccountModerationNotes < ActiveRecord::Migration[5.1]
   def change
-    add_foreign_key :account_moderation_notes, :accounts
+    safety_assured { add_foreign_key :account_moderation_notes, :accounts }
   end
 end

db/migrate/20171118012443_add_moved_to_account_id_to_accounts.rb

 class AddMovedToAccountIdToAccounts < ActiveRecord::Migration[5.1]
   def change
     add_column :accounts, :moved_to_account_id, :bigint, null: true, default: nil
-    add_foreign_key :accounts, :accounts, column: :moved_to_account_id, on_delete: :nullify
+    safety_assured { add_foreign_key :accounts, :accounts, column: :moved_to_account_id, on_delete: :nullify }
   end
 end