[table editor] Change virtual dataset won't work

How to reproduce the bug

1. Go to a chart using virtual dataset, which has sql query

2. Click on Edit dataset

3. change sql: (in my case, change > '2021-07-01' to = '2021-07-01' )

4. save it

5. It looks dataset is updated with success message

6. But if you open Edit dataset modal, yo will see old sql

7. in the API, you can see the old sql is sent out in the update API:

Environment

(please complete the following information):

• superset version: superset version
• python version: python --version
• node.js version: node -v
• any feature flags active:

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven’t found one similar.

Additional context

cc @junlincc

[junlincc]

thanks for filing, we also noticed it. moved it to p0 this is pretty sever so we are picking it up from you guys. @eschutho

[zhaoyongjie]

@graceguo-supercat I am on it.