libvirt.spec.in: require systemd-container on >= f24

The systemd-machined tools libvirt uses were split into a
systemd-container RPM. Without depending on this, libvirt
may silently fallback to the non-systemd cgroup impl which
is not desirable.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

libvirt.spec.in

@@ -619,6 +619,9 @@ Requires: gzip
 Requires: bzip2
 Requires: lzop
 Requires: xz
+%if 0%{?fedora} >= 24
+Requires: systemd-container
+%endif
 
 %description daemon-driver-qemu
 The qemu driver plugin for the libvirtd daemon, providing
@@ -634,6 +637,9 @@ Group: Development/Libraries
 Requires: libvirt-daemon = %{version}-%{release}
 # There really is a hard cross-driver dependency here
 Requires: libvirt-daemon-driver-network = %{version}-%{release}
+%if 0%{?fedora} >= 24
+Requires: systemd-container
+%endif
 
 %description daemon-driver-lxc
 The LXC driver plugin for the libvirtd daemon, providing