Configure FreeRadius to send CoA-ACK

[Gennaro Leo]

This is the output debug, honestly I can't understand why CoA-NAK is sent.

rad_recv: CoA-Request packet from host 10.42.154.231 port
35046***Packet***  Code:              43
        NAS-IP-Address = 10.10.10.10
        Acct-Session-Id = "#000111#1#002"
        ERX-Attr-58 = 0xa33c42d191954d27c5d8c4d9a2c5f53a6bc9
        ERX-Attr-59 = 0xa33c428191959627c5d8c4d9a2c5f53a6bc9
        ERX-Attr-60 = 0xa33c42dbbb0fab27c5d8c4d9a2c5f53a6bc9
        ERX-Attr-61 = 0xa33c42d191df7427c5d8c4d9a2c5f53a6bc9
server coa {
No such virtual server "coa"
No such virtual server "coa"
} # server coa
Sending CoA-NAK of id 0 to 10.42.154.231 port 35046
Finished request 1.