Remove isc_bind9 global option from libraries
The libisc has a global "knob" that decides whether the library is used from BIND 9 or other projects. As we have decided to make the libraries private to BIND 9, the knob can go.
The libisc has a global "knob" that decides whether the library is used from BIND 9 or other projects. As we have decided to make the libraries private to BIND 9, the knob can go.