Newer versions of Intel AMT use digest auth with different parameters depending on what the server supports. Parsing currently fails when parameters other than "auth" are provided. Running the iamt example I get the following output:

~/src/iamt/example$ ./example 
panic: failed to parse auth header challenge is bad, unexpected token: [realm="Digest:D15CF4BF35F8D0F6CEFD0AA92D4D496A"  nonce="jyTb0E1UAAAAAAAADG/kz8n0/Pb6clW5" stale="false" qop="auth auth-int  auth"]

goroutine 1 [running]:
main.main()
        ~src/iamt/example/main.go:22 +0x272

With my changes, I now get a successful result:

~/src/iamt/example$ ./example 
Is powered on? true

I'm currently using a Minisforum MS-01 with Intel AMT v16 and want to deploy a CAPT cluster.

This PR fixes the parse since, parameters other than "auth" are not supported anyway according to this comment.