While PVE and PMG use a rather brittle "replace whole config" style on
their DNS entry CRUD API, the PBS one was made with a per-entry level
granularity, so that single entries can modified, or deleted, without
touching the others.
But the UI from the widget-toolkit was made for the older PVE/PMG
behavior and did not sent along the delete-array of to-be-deleted
keys.
Since widget-toolkit commit 8d161ac ("dns: update comment to avoid
coupling to downstream dependency") the DNS edit window supports
opting into that by setting the new `deleteEmpty` config parameter.
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
[ TL: expand commit message ]
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>