Remove readonly fields from fields tuple before create model_form
Remove readonly fields from fields tuple before create model_form

It solves the problem with sqla, I don't know if the other backends have the same issue.

If you pass readonly fields in `only` parameter, WTF try to update these fields and breaks because they are not defined.
syrusakbary/Flask-SuperAdmin,syrusakbary/Flask-SuperAdmin,syrusakbary/Flask-SuperAdmin,syrusakbary/Flask-SuperAdmin