Fix old migrations failing because of new version of `strong_migrations`

db/migrate/20171009222537_create_keyword_mutes.rb

@@ -7,6 +7,6 @@ class CreateKeywordMutes < ActiveRecord::Migration[5.1]
       t.timestamps
     end
 
-    add_foreign_key :keyword_mutes, :accounts, on_delete: :cascade
+    safety_assured { add_foreign_key :keyword_mutes, :accounts, on_delete: :cascade }
   end
 end

db/migrate/20180410220657_create_bookmarks.rb

@@ -7,8 +7,8 @@ class CreateBookmarks < ActiveRecord::Migration[5.1]
       t.timestamps
     end
 
-    add_foreign_key :bookmarks, :accounts, column: :account_id, on_delete: :cascade
-    add_foreign_key :bookmarks, :statuses, column: :status_id, on_delete: :cascade
+    safety_assured { add_foreign_key :bookmarks, :accounts, column: :account_id, on_delete: :cascade }
+    safety_assured { add_foreign_key :bookmarks, :statuses, column: :status_id, on_delete: :cascade }
     add_index :bookmarks, [:account_id, :status_id], unique: true
   end
 end