simplify installation of apport hook

Today we have two ways to install which seem redundant:

--- a/debian/libvirt-daemon-system.dirs
+++ b/debian/libvirt-daemon-system.dirs
@@ -2,6 +2,7 @@ etc/libvirt/hooks
 etc/libvirt/nwfilter
 etc/libvirt/qemu/networks
 etc/libvirt/qemu/networks/autostart
+usr/share/apport/package-hooks

--- a/debian/libvirt-daemon.install
+++ b/debian/libvirt-daemon.install
@@ -20,6 +20,7 @@ usr/lib/libvirt/libvirt_parthelper
 usr/sbin/libvirtd
 usr/sbin/virtlockd
 usr/sbin/virtlogd
+usr/share/apport/package-hooks/source_libvirt.py

AND

+override_dh_auto_install:
+ mkdir -p debian/tmp/usr/share/apport/package-hooks
+ cp -f debian/libvirt-daemon.apport \
+ debian/tmp/usr/share/apport/package-hooks/source_libvirt.py
+ dh_auto_install

This should be simplified down to one.
The d/rules only makes sense if the make another try to upstream to Debian to only do that if vendor = Ubuntu.