Comment 0 for bug 1497330

Repro:
1. Start vm
2. Connect DVR router to the vm's subnet
3. Check router is scheduled to the l3 agent on vm's compute node
4. Delete vm (this is the only/last vm on the compute node)
5. Check router is not scheduled to the l3 agent on the compute node
Actual: router is still scheduled to the node with no vms

This is a regression from commit commit 5bac0992d2342791ae270c60a3990e721310ad05