Install libosinfo on n-cpu nodes

As of 9de8f7230d069e4da9736f09ad5d17773315b476 nova is now attempting
to import libosinfo packages, so install them for goodness sake.

Change-Id: Ib481dda475dd2975a513052478be0007aa1cf4a8
Related-Bug: #1543288
diff --git a/files/debs/n-cpu b/files/debs/n-cpu
index 0da57ee..69ac430 100644
--- a/files/debs/n-cpu
+++ b/files/debs/n-cpu
@@ -1,5 +1,6 @@
 cryptsetup
 genisoimage
+gir1.2-libosinfo-1.0
 lvm2 # NOPRIME
 open-iscsi
 python-guestfs # NOPRIME