Prevent create auditing record when update entity in Dynamic CRM

Hello all,

In my post plug-in, i have to update entity Contact

I use this code below to update it 

And when I see in Auditing History, i see 2 record Update but one is emty (no field is updated)

Any idea for it, please?

If my question/answer can help you, please give me a points :) ----You may be disappointed if you fail, but you are doomed if you don't try---