Add missing [privsep_entrypoint]/helper_command

Closes-Bug: ATMOSPHERE-648
Change-Id: I12243527ad763bb249195220093717d68de050f6
diff --git a/images/glance/Dockerfile b/images/glance/Dockerfile
index 62509ec..062924d 100644
--- a/images/glance/Dockerfile
+++ b/images/glance/Dockerfile
@@ -24,7 +24,7 @@
 RUN <<EOF bash -xe
 apt-get update -qq
 apt-get install -qq -y --no-install-recommends \
-    ceph-common lsscsi nvme-cli python3-rados python3-rbd qemu-block-extra qemu-utils sysfsutils udev util-linux
+    ceph-common dmidecode lsscsi nvme-cli python3-rados python3-rbd qemu-block-extra qemu-utils sysfsutils udev util-linux
 apt-get clean
 rm -rf /var/lib/apt/lists/*
 EOF