Fix vapigen on uninstalled environment
Fix vapigen on uninstalled environment

JGulic/libvirt-glib,libvirt/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,JGulic/libvirt-glib,libvirt/libvirt-glib,JGulic/libvirt-glib,libvirt/libvirt-glib