Fix data models (#13444)

### What problem does this PR solve?

Since database model is updated in python version, go server also need
to update

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/admin/service.go

@@ -94,7 +94,7 @@ type UserInfo struct {
 	Email      string
 	Nickname   string
 	IsActive   string
-	CreateTime int64
+	CreateTime *int64
 	UpdateTime *int64
 }