Description of problem:
When rhsm credentials (rhsm_username, rhsm_password, etc.) for one destination is wrong, then gathering host-to-guest mapping is terminated. This bug is related to new heartbeat REST API call and other problems with connection (too many requests, etc.) causes termination of gathering guest-to-host mapping too.

Version-Release number of selected component (if applicable):
virt-who-0.24.7-1.el7

How reproducible:
100%

Steps to Reproduce:
1. Create configuration file with wrong credentials. Something like this:

[local_libvirt]
type=libvirt
server=qemu:///system
owner=admin

rhsm_hostname=svice
rhsm_port=8443
rhsm_username=admin
rhsm_password=wrong_password
rhsm_org=admin
rhsm_prefix=/candlepin
rhsm_insecure=1

2. Try to run virt-who

[root@localhost ~]# virt-who -d -o -c /path/to/config/file.conf

Actual results:

2019-06-20 17:49:48,603 [virtwho.destination_1059304658735338682 ERROR] MainProcess(8171):Thread-3 @virt.py:run:421 - Thread 'destination_1059304658735338682' fails with exception:
Traceback (most recent call last):
  File "virtwho/virt/virt.py", line 412, in run
    self._run()
  File "virtwho/virt/virt.py", line 368, in _run
    self._send_data(data_to_send)
  File "virtwho/virt/virt.py", line 604, in _send_data
    self.dest.hypervisorHeartbeat(config=self.config, options=self.options)
  File "virtwho/manager/subscriptionmanager/subscriptionmanager.py", line 264, in hypervisorHeartbeat
    result = connection.hypervisorHeartbeat(config['owner'], named_options)
  File "/home/jiri/github/candlepin/subscription_manager/src/rhsm/connection.py", line 1063, in hypervisorHeartbeat
    return self.conn.request_put(url)
  File "/home/jiri/github/candlepin/subscription_manager/src/rhsm/connection.py", line 735, in request_put
    return self._request("PUT", method, params, headers=headers)
  File "/home/jiri/github/candlepin/subscription_manager/src/rhsm/connection.py", line 752, in _request
    info=info, headers=headers)
  File "/home/jiri/github/candlepin/subscription_manager/src/rhsm/connection.py", line 627, in _request
    self.validateResponse(result, request_type, handler)
  File "/home/jiri/github/candlepin/subscription_manager/src/rhsm/connection.py", line 689, in validateResponse
    raise RestlibException(response['status'], error_msg, response.get('headers'))
RestlibException: HTTP error (401 - Unauthorized): Invalid Credentials
2019-06-20 17:49:48,604 [virtwho.destination_1059304658735338682 INFO] MainProcess(8171):Thread-3 @virt.py:_send_data:615 - Error report received
2019-06-20 17:49:48,604 [virtwho.destination_1059304658735338682 DEBUG] MainProcess(8171):Thread-3 @virt.py:run:435 - Thread 'destination_1059304658735338682' stopped after running once
2019-06-20 17:49:49,564 [virtwho.main DEBUG] MainProcess(8171):MainThread @__main__.py:main:25 - virt-who terminated
2019-06-20 17:49:49,564 [virtwho.main DEBUG] MainProcess(8171):MainThread @executor.py:terminate:225 - virt-who is shutting down

Expected results:
Log message with error (traceback) is printed and Host-to-guest mapping is gathered and can be used for other destination with valid credentials.

Additional info: