[master] fix build error when IP_TOS is undefined
[master] fix build error when IP_TOS is undefined

each/bind9-collab,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9