Disabling Cpanel login popup

The HTTP Authentication Dialog ("Popup") is not a function of visiting /cpanel. Even if you were to access :2082 directly, you would receive this dialog box.

This can be avoided by using the lesser secure authentication method of cookies. In WHM -> Server Configuration -> Tweak Settings simply check the box for Disable Http Authentication for cPanel/WebMail/WHM Logins (forces cookie authentication) and click save at the bottom of the page.