Description of problem:
If there is a blank after uuid and before comma when set filter_host_uuids or  exlude_host_uuid, virt-who can't recognize that uuid . 
eg:
filter_host_uuids="77ea4d56-2176-2518-74f6-d350749401dd" ,"86b2bd00-8bad-11e2-87f4-6c3be514699d"
exclude_host_uuids="77ea4d56-2176-2518-74f6-d350749401dd" ,"86b2bd00-8bad-11e2-87f4-6c3be514699d"

Version-Release number of selected component (if applicable):
virt-who-0.16-7.el6.noarch
subscription-manager-1.16.8-5.el6.x86_64
python-rhsm-1.16.6-1.el6.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Register system to stage canlepin.
2. Configure virt-who run at esx mode in /etc/virt-who.d/esx, setting to filter two host's uuid, make sure there is a blank before the comma which separate these two uuids
[root@ibm-x3250m4-16 virt-who.d]# cat /etc/virt-who.d/esx 
[test-esx1]
type=esx
server=10.73.2.95
username=Administrator
encrypted_password=d7e94e75ce18ef1be41f86a3dc017b0f
owner=7715246
env=7715246
filter_host_uuids="77ea4d56-2176-2518-74f6-d350749401dd" ,"86b2bd00-8bad-11e2-87f4-6c3be514699d"
3. Restart virt-who and check virt-who's log
[root@ibm-x3250m4-16 virt-who.d]# service virt-who restart && tail -f /var/log/rhsm/rhsm.log 
Stopping virt-who:                                         [FAILED]
Starting virt-who:                                         [  OK  ]
.......................
2016-03-18 02:09:07,164 [virtwho.main DEBUG] MainProcess(28285):MainThread @subscriptionmanager.py:hypervisorCheckIn:162 - Checking if server has capability 'hypervisor_async'
2016-03-18 02:09:07,704 [virtwho.main DEBUG] MainProcess(28285):MainThread @subscriptionmanager.py:hypervisorCheckIn:174 - Server does not have 'hypervisors_async' capability
2016-03-18 02:09:07,704 [virtwho.main INFO] MainProcess(28285):MainThread @subscriptionmanager.py:hypervisorCheckIn:185 - Sending update in hosts-to-guests mapping for config "test-esx1": 1 hypervisors and 1 guests found
2016-03-18 02:09:07,704 [virtwho.main DEBUG] MainProcess(28285):MainThread 

======== 77ea4d56-2176-2518-74f6-d350749401dd has been skipped =========
@subscriptionmanager.py:hypervisorCheckIn:186 - Host-to-guest mapping: {
    "86b2bd00-8bad-11e2-87f4-6c3be514699d": [
        {
            "guestId": "420660d6-13f5-23bf-808b-161498bf1702", 
            "state": 1, 
            "attributes": {
                "active": 1, 
                "hypervisorVersion": "6.0.0", 
                "virtWhoType": "esx", 
                "hypervisorType": "VMware ESXi"
            }
        }
    ]
}
2016-03-18 02:09:08,469 [virtwho.main DEBUG] MainProcess(28285):MainThread @virtwho.py:send_report:161 - Report for config "test-esx1" sent

Actual results:
If there is a blank space between uuids, the uuid before blank space is invalid.

Expected results:
In filter_host_uuids or exclude_host_uuids, no matter blank before or behind uuid, the uuid should work.

Additional info: