I got the same massage, I see this topic is opened for over a year however maybe somebody still overwatch it .
I see a knowlegdebase article whice descibe the warning.

However I can never find how to reset the warning

Can anyone help?

Hi @Peter_1966  @dinoh  
The warning is generated when a third-party client/script is using the admin username to make REST end-points calls. 

The warning also includes an IP address from where you can isolate which client/script is using the admin account to make REST API calls, it could be any third-party vendor or a script written by you. 

You can create a new username and use that to authenticate REST API without an alert being raised.

If the issue is still not resolved, can you tell us more details about your infrastructure like AOS Version, NCC version, frequency of receiving the warning and which IP address is being shown in the warning and what is the IP Address associated with?

Hope that helps.