Make dependency on libvirt dynamic

Fixes bug 1184960

Change-Id: If702807d9ae326bf216a2e076ce61062045d7c6b
diff --git a/files/apts/nova b/files/apts/nova
index c24333c..6a7ef74 100644
--- a/files/apts/nova
+++ b/files/apts/nova
@@ -12,8 +12,8 @@
 ebtables
 sqlite3
 sudo
-kvm
-qemu # dist:wheezy,jessie
+kvm # NOPRIME
+qemu # dist:wheezy,jessie NOPRIME
 libvirt-bin # NOPRIME
 libjs-jquery-tablesorter # Needed for coverage html reports
 vlan
@@ -27,7 +27,7 @@
 python-migrate
 python-gflags
 python-greenlet
-python-libvirt
+python-libvirt # NOPRIME
 python-libxml2
 python-routes
 python-netaddr