Fix more assertion counts.

Follow up to e45f388e.

railties/test/generators/scaffold_generator_test.rb

@@ -488,7 +488,7 @@ def test_scaffold_tests_pass_by_default_inside_mountable_engine
         `bin/rails g scaffold User name:string age:integer;
         bin/rails db:migrate`
       end
-      assert_match(/8 runs, 13 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
+      assert_match(/8 runs, 10 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
     end
   end
 
@@ -502,7 +502,7 @@ def test_scaffold_tests_pass_by_default_inside_full_engine
         `bin/rails g scaffold User name:string age:integer;
         bin/rails db:migrate`
       end
-      assert_match(/8 runs, 13 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
+      assert_match(/8 runs, 10 assertions, 0 failures, 0 errors/, `bin/rails test 2>&1`)
     end
   end