Description of problem:
when block-based SD for iso, iso is not ejected from the vm when ejected through admin portal

Version-Release number of selected component (if applicable):
4.3.4.3-0.1.el7

How reproducible:
everytime

Steps to Reproduce:
1. start the vm with iso from blockbased storage
2. eject iso in "Change CD" in admin portal
3. put blockbased storage into maintenance
4, try to migrate the vm to the different host

Actual results:
migration will fail with error:

2019-08-01 08:53:16,676+02 ERROR [org.ovirt.engine.core.vdsbroker.monitoring.VmAnalyzer] (ForkJoinPool-1-worker-1) [] Migration of VM 'test-iso' to host 'host1' failed: Bad volume specification {'address': {'bus': '1', 'controller': '0', 'type': 'drive', 'target': '0', 'unit': '0'}, 'index': 2, 'iface': 'ide', 'apparentsize': 0, 'specParams': {}, 'imageID': 'fbf703d6-60fb-421f-9506-60086aeb67af', 'readonly': True, 'truesize': 0, 'type': 'disk', 'domainID': '68c612ca-64b3-48d6-bacb-ecfb36972943', 'reqsize': '0', 'format': 'raw', 'poolID': '58ea5064-996f-11e9-9e4a-0001020304e5', 'device': 'cdrom', 'path': '', 'propagateErrors': 'report', 'name': 'hdc', 'bootOrder': '2', 'volumeID': '4bbf9334-8bec-4c38-927d-88d5833ad523', 'diskType': 'file', 'alias': 'ua-648e9eef-eb94-4db6-bce4-b16d5610bfd2', 'discard': False, 'volumeChain': [{'domainID': '68c612ca-64b3-48d6-bacb-ecfb36972943', 'leaseOffset': 105906176, 'volumeID': '4bbf9334-8bec-4c38-927d-88d5833ad523', 'leasePath': '/dev/68c612ca-64b3-48d6-bacb-ecfb36972943/leases', 'imageID': 'fbf703d6-60fb-421f-9506-60086aeb67af', 'path': '/rhev/data-center/mnt/blockSD/68c612ca-64b3-48d6-bacb-ecfb36972943/images/fbf703d6-60fb-421f-9506-60086aeb67af/4bbf9334-8bec-4c38-927d-88d5833ad523'}]}.


Expected results:
either iso will be ejected or engine will not let SD to be switched to the maintenance

Additional info: