Description of problem:
If the hypervisor has been registered to satellite, register it again will result in failed to associate host/guest mapping info.

Version-Release number of selected component (if applicable):
virt-who-0.17-10.el7sat.noarch
Satellite6.2.7-sp3

How reproducible:
Always

Steps to Reproduce:
1. Register guest to satellite6.2.7

******************The first time report hostname*******************
2. Configure virt-who report hypervisor's hostname to satellite
[root@bkr-hv03-guest20 virt-who.d]# cat /etc/virt-who.d/hyperv1 
[test-hyperv2]
type=hyperv
server=10.73.5.227
username=virtwho\administrator
encrypted_password=3ce98c643e783a83cc247b00ea3d2d3c
owner=org1
env=Library 
rhsm_username=admin
rhsm_encrypted_password=ce6d7d014da9d0a7f5590bdd15c376d2
rhsm_prefix=/rhsm
rhsm_port=443
rhsm_hostname=hp-ml370g6-01.rhts.eng.bos.redhat.com
hypervisor_id=hostname              ===============> Configure report hostname 

3. Start virt-who and check virt-who's log
[root@bkr-hv03-guest20 virt-who.d]# service virt-who restart && tail -f /var/log/rhsm/rhsm.log
2017-01-25 04:09:02,263 [virtwho.main DEBUG] MainProcess(1427):MainThread @subscriptionmanager.py:hypervisorCheckIn:195 - Host-to-guest mapping: {
    "virtwho_03": [      =======>Virt-who send hostname to satellite
        {
            "guestId": "5EF3A910-F00F-7447-A995-2BE57CA30A6F", 
            "state": 1, 
            "attributes": {
                "active": 1, 
                "virtWhoType": "hyperv"
            }
        }
    ]
}
2017-01-25 04:09:04,525 [virtwho.main DEBUG] MainProcess(1427):MainThread @executor.py:send_report:101 - Report for config "test-hyperv2" sent

4. In satellite webUI, go to Hosts--> Content host, it will show a new hypervisor "virt-who-virtwho-03-3"

5. In satellite webUI, go to Hosts--> Content host-->[Guest], click guest name , check guest's Virtual Host "virt-who-virtwho-03-3", see screenshot show_hostname.jpeg(It's correct)

******************The second time report hostuuid*******************
6. Modify virt-who's configure to report uuid instead of hostname as the following:
[root@bkr-hv03-guest20 virt-who.d]# cat /etc/virt-who.d/hyperv1 
[test-hyperv2]
type=hyperv
server=10.73.5.227
username=virtwho\administrator
encrypted_password=3ce98c643e783a83cc247b00ea3d2d3c
owner=org1
env=Library 
rhsm_username=admin
rhsm_encrypted_password=ce6d7d014da9d0a7f5590bdd15c376d2
rhsm_prefix=/rhsm
rhsm_port=443
rhsm_hostname=hp-ml370g6-01.rhts.eng.bos.redhat.com
hypervisor_id=uuid              ===============> Configure report uuid

7. Restart virt-who and check virt-who's log
[root@bkr-hv03-guest20 virt-who.d]# service virt-who restart && tail -f /var/log/rhsm/rhsm.log
2017-01-25 04:10:00,758 [virtwho.main DEBUG] MainProcess(1450):MainThread @subscriptionmanager.py:hypervisorCheckIn:195 - Host-to-guest mapping: {
    "564D84C1-0A16-E227-067D-472D286A9AC2": [  =======>Virt-who send uuid to satellite
        {
            "guestId": "5EF3A910-F00F-7447-A995-2BE57CA30A6F", 
            "state": 1, 
            "attributes": {
                "active": 1, 
                "virtWhoType": "hyperv"
            }
        }
    ]
}
2017-01-25 04:10:02,762 [virtwho.main DEBUG] MainProcess(1450):MainThread @executor.py:send_report:101 - Report for config "test-hyperv2" sent

8. In satellite webUI, go to Hosts--> Content host, it will show a new hypervisor "virt-who-564D84C1-0A16-E227-067D-472D286A9AC2-3"

9. In satellite webUI, go to Hosts--> Content host-->[Guest], click guest name , check guest's Virtual Host "virt-who-564D84C1-0A16-E227-067D-472D286A9AC2-3", see screenshot show_uuid.jpeg(It's correct)

******************The third time report hostname again*******************
10. Configure virt-who report hypervisor's hostname to satellite again.
[root@bkr-hv03-guest20 virt-who.d]# cat /etc/virt-who.d/hyperv1 
[test-hyperv2]
type=hyperv
server=10.73.5.227
username=virtwho\administrator
encrypted_password=3ce98c643e783a83cc247b00ea3d2d3c
owner=org1
env=Library 
rhsm_username=admin
rhsm_encrypted_password=ce6d7d014da9d0a7f5590bdd15c376d2
rhsm_prefix=/rhsm
rhsm_port=443
rhsm_hostname=hp-ml370g6-01.rhts.eng.bos.redhat.com
hypervisor_id=hostname              ===============> Configure report hostname 

11. Start virt-who and check virt-who's log
[root@bkr-hv03-guest20 virt-who.d]# service virt-who restart && tail -f /var/log/rhsm/rhsm.log
2017-01-25 04:10:40,008 [virtwho.main DEBUG] MainProcess(1471):MainThread @subscriptionmanager.py:hypervisorCheckIn:195 - Host-to-guest mapping: {
    "virtwho_03": [          =======>Virt-who send hostname to satellite
        {
            "guestId": "5EF3A910-F00F-7447-A995-2BE57CA30A6F", 
            "state": 1, 
            "attributes": {
                "active": 1, 
                "virtWhoType": "hyperv"
            }
        }
    ]
}
2017-01-25 04:10:40,711 [virtwho.main DEBUG] MainProcess(1471):MainThread @executor.py:send_report:101 - Report for config "test-hyperv2" sent

12. In satellite webUI, go to Hosts--> Content host-->[Guest], click guest name , check guest's Virtual Host 


Actual results:
Although virt-who send hypervisor's hostname to satellite, it still show guest's Virtual Host "virt-who-564D84C1-0A16-E227-067D-472D286A9AC2-3"

Expected results:
Since virt-who has updated the mapping info to satellite, it should update guest's Virtual Host to "virt-who-virtwho-03-3" in webUI.

Additional info: