Description of problem:
configure virt-who with hyper-v, sometimes, virt-who will show error message:
Unable to send data: Communication with subscription manager failed with code 500: Task 280df62d-63f6-49fb-a2c3-bf02d299b70e: ActiveRecord::StatementInvalid: PG::Error: ERROR:  null value in column "host_id" violates not-null constraint
: INSERT INTO "katello_subscription_facets" ("autoheal", "registered_at", "uuid") VALUES ($1, $2, $3) RETURNING "id"


Version-Release number of selected component (if applicable):
- Satellite-6.2.0-20160518.1
- RHEL-7.3-20160517.n.0 Server x86_64
- virt-who-0.17-1.el7.noarch
- subscription-manager-1.17.6-1.el7.x86_64

How reproducible:
80%

Steps to Reproduce:
1. deploy Satellite-6.2.0-20160518.1

2. install host with RHEL-7.3-20160517.n.0 Server x86_64 for testing

3. register host to sat6.2

4. run virt-who with hyper-v mode
# virt-who --hyperv --hyperv-owner=ACME_Corporation --hyperv-env=Library --hyperv-server=10.73.5.220 --hyperv-username=Administrator --esx-password=Welcome1 -d
2016-05-20 05:18:26,878 [virtwho.init INFO] MainProcess(32401):MainThread @main.py:main:157 - Using configuration "env/cmdline" ("hyperv" mode)
2016-05-20 05:18:26,879 [virtwho.init INFO] MainProcess(32401):MainThread @main.py:main:159 - Using reporter_id='hp-z220-12.qe.lab.eng.nay.redhat.com-981fc52581194b43af6115db34651494'
2016-05-20 05:18:26,880 [virtwho.main DEBUG] MainProcess(32401):MainThread @executor.py:run:171 - Starting infinite loop with 60 seconds interval
2016-05-20 05:18:26,906 [virtwho.env_cmdline DEBUG] MainProcess(32401):MainThread @hyperv.py:__init__:472 - Hyper-V url: http://10.73.5.220:5985/wsman
2016-05-20 05:18:26,907 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @virt.py:run:364 - Virt backend 'env/cmdline' started
2016-05-20 05:18:26,920 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:retry_ntlm_negotitate:64 - Using NTLM authentication
2016-05-20 05:18:26,923 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:retry_ntlm_authenticate:77 - Sending NTLM authentication data
2016-05-20 05:18:26,942 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:retry_ntlm_authenticate:100 - NTLM authentication successful
2016-05-20 05:18:26,944 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:getHostGuestMapping:520 - Unable to enumerate using root/virtualization namespace, trying root/virtualization/v2 namespace
2016-05-20 05:18:29,545 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @virt.py:enqueue:357 - Report for config "env/cmdline" gathered, putting to queue for sending
2016-05-20 05:18:29,555 [virtwho.main DEBUG] MainProcess(32401):MainThread @subscriptionmanager.py:_connect:123 - Authenticating with certificate: /etc/pki/consumer/cert.pem
2016-05-20 05:19:14,099 [virtwho.main DEBUG] MainProcess(32401):MainThread @subscriptionmanager.py:hypervisorCheckIn:168 - Checking if server has capability 'hypervisor_async'
2016-05-20 05:19:27,609 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:retry_ntlm_negotitate:64 - Using NTLM authentication
2016-05-20 05:19:27,612 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:retry_ntlm_authenticate:77 - Sending NTLM authentication data
2016-05-20 05:19:27,636 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @hyperv.py:retry_ntlm_authenticate:100 - NTLM authentication successful
2016-05-20 05:19:30,215 [virtwho.env_cmdline DEBUG] HyperV-1(32408):MainThread @virt.py:enqueue:357 - Report for config "env/cmdline" gathered, putting to queue for sending
2016-05-20 05:19:38,395 [virtwho.main DEBUG] MainProcess(32401):MainThread @subscriptionmanager.py:hypervisorCheckIn:180 - Server does not have 'hypervisors_async' capability
2016-05-20 05:19:38,395 [virtwho.main INFO] MainProcess(32401):MainThread @subscriptionmanager.py:hypervisorCheckIn:191 - Sending update in hosts-to-guests mapping for config "env/cmdline": 1 hypervisors and 1 guests found
2016-05-20 05:19:38,395 [virtwho.main DEBUG] MainProcess(32401):MainThread @subscriptionmanager.py:hypervisorCheckIn:192 - Host-to-guest mapping: {
    "564D900A-2E82-672D-2CB7-C17F0B3FF876": [
        {
            "guestId": "EBBF4A99-85AD-0947-AB31-45DD18FE96E5", 
            "state": 1, 
            "attributes": {
                "active": 1, 
                "virtWhoType": "hyperv"
            }
        }
    ]
}
2016-05-20 05:20:07,550 [virtwho.main ERROR] MainProcess(32401):MainThread @executor.py:send:143 - Unable to send data: Communication with subscription manager failed with code 500: Task c712acda-3ba0-4102-9060-b82e78c1bc15: ActiveRecord::StatementInvalid: PG::Error: ERROR:  null value in column "host_id" violates not-null constraint
: INSERT INTO "katello_subscription_facets" ("autoheal", "registered_at", "uuid") VALUES ($1, $2, $3) RETURNING "id"
2016-05-20 05:20:07,550 [virtwho.main DEBUG] MainProcess(32401):MainThread @executor.py:send_report:108 - Report from "env/cmdline" failed to sent


Actual results:
sent mapping info to sat6.2 failed
Communication with subscription manager failed with code 500
ERROR:  null value in column "host_id" violates not-null constraint
: INSERT INTO "katello_subscription_facets" ("autoheal", "registered_at", "uuid") VALUES ($1, $2, $3) RETURNING "id"

Expected results:
virt-who should send the info normally

Additional info: