Virtual Router leaks floating-IP leases on `onevrouter delete`

[xorel]

Description

Deleting a Virtual Router that has two or more --float NICs leaks floating-IP
leases. onevrouter delete frees one floating lease but leaves the others
orphaned on the Virtual Network as R:<vrouter_id> — the lease persists even
though the Virtual Router no longer exists.

The orphaned lease cannot be freed with onevnet release or onevnet rmar
(the address is reported as in use); only onedb fsck clears it. Repeated
VRouter create/delete cycles therefore fill the address range with dead leases
until new VRouters fail with Cannot get IP/MAC lease from virtual network.

Version

OpenNebula 7.3.80. Git-bisected to the range 2c8fdf2..b490213; the only
address-management change in that range is deb127c59b "F one#6534: Support
for assigning IPs to several VMs" (the single-owner → multi-owner
AddressRange rewrite), which is the likely cause.

Steps to reproduce

1. Create two Virtual Networks, each with an IPv4 address range (netA, netB).
2. Create a Virtual Router and instantiate it from a VROUTER=YES VM template
   (one VR VM, any OS image).
3. Wait for the Virtual Router VM to reach RUNNING.
4. onevrouter nic-attach <vr> --network netA --float --ip <ipA>
5. After the VR VM leaves the HOTPLUG_NIC state, run
   onevrouter nic-attach <vr> --network netB --float --ip <ipB>
6. Check both networks — onevnet show reports USED LEASES : 1 on each.
7. onevrouter delete <vr>

Expected

Both floating-IP leases released — USED LEASES : 0 on netA and netB.

Actual

Only one lease is released. onevnet show netB still lists a lease R:<vr>
for <ipB>, although Virtual Router <vr> no longer exists. The lease is
unremovable via onevnet release / onevnet rmar.

A Virtual Router with a single --float NIC does not leak; the problem needs
two or more floating NICs.