update_at time is not consistent

[AWaterColorPen]

GORM Playground Link

go-gorm/playground#288

Description

For example:
when we call updates method, user.update_at is "2021-02-26 20:47:16.823720459Z" .
But the UPDATE sql uses "update_at"="2021-02-26 20:47:16.824Z", and SELECT sql uses "update_at"="2021-02-26 20:47:16.823Z"

update_at is not consistent.

I think update_at should be consistent. And it should be no error for this case

[jinzhu]

this should been fixed.