debian: Allow apt-get post hook to fail gracefully (won't work in chroot)

network/00notiy-hook

@@ -1 +1 @@
-DPkg::Post-Invoke {"/usr/lib/qubes/qrexec-client-vm dom0 qubes.NotifyUpdates /bin/sh -c 'echo 0'";};
+DPkg::Post-Invoke {"/usr/lib/qubes/qrexec-client-vm dom0 qubes.NotifyUpdates /bin/sh -c 'echo 0' || true";};