nss: Remove RES_USE_INET6 usage
nss: Remove RES_USE_INET6 usage

The recent deprecation in glibc (commit b76e065991ec) means the
module will fail to build entirely:

  nss/libvirt_nss.c: In function '_nss_libvirt_gethostbyname_r':
  nss/libvirt_nss.c:363:13: error: RES_USE_INET6 is deprecated [-Werror]
     int af = ((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This resolver option was removed shortly after being introduced,
and application using it are already broken anyway.

olafhering/libvirt,jardasgit/libvirt,zippy2/libvirt,jardasgit/libvirt,zippy2/libvirt,andreabolognani/libvirt,crobinso/libvirt,libvirt/libvirt,datto/libvirt,libvirt/libvirt,andreabolognani/libvirt,libvirt/libvirt,olafhering/libvirt,jardasgit/libvirt,taget/libvirt,crobinso/libvirt,jfehlig/libvirt,eskultety/libvirt,jardasgit/libvirt,datto/libvirt,andreabolognani/libvirt,zippy2/libvirt,nertpinx/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,datto/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,datto/libvirt,jfehlig/libvirt,crobinso/libvirt,datto/libvirt,olafhering/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,taget/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,taget/libvirt,olafhering/libvirt,andreabolognani/libvirt,zippy2/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,taget/libvirt,eskultety/libvirt,eskultety/libvirt,eskultety/libvirt,eskultety/libvirt,taget/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,crobinso/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,libvirt/libvirt