External snapshots are created world-readable when connecting via qemu+ssh://root
Description of problem:
External snapshots are created with world-readable permissions when connecting via `qemu+ssh://root`.
Steps to reproduce:
1. Create a VM over `qemu+ssh://root@$SERVER/system`
2. Create an external snapshot via virt-manager or with `virsh snapshot-create-as  --domain testvm --name test --disk-only --diskspec vda,file=/var/lib/libvirt/images/test.qcow2  --atomic`
3. `ls -l /var/lib/libvirt/images/test.qcow2`
Additional information:
Issue doesn't seem to go away by adding `umask 077` in `$HOME/.profile`