Description of problem:
use vim to open a config file such as: vi /etc/virt-who.d/esx.conf, if don't quit vim, there is a ".esx.conf.swp" file created, virt-who will check the .swp file and feedback error message.
the expected result is: virt-who shouldn't check the .esx.conf.swp file.


Version-Release number of selected component (if applicable):
virt-who-0.16-7.el6.noarch
subscription-manager-1.16.8-8.el6.x86_64
python-rhsm-1.16.6-1.el6.x86_64

How reproducible:
always

Steps to Reproduce:
1. use vim edit a config file:
# vim /etc/virt-who.d/esx.conf
[test-esx]
type=esx
server=10.73.2.95
username=Administrator
#password=Welcome1!
owner=ACME_Corporation
env=Library

2. save the file, but don't quit vim, make sure esx.conf.swp exist

3. restart virt-who and check rhsm.log
2016-04-01 11:33:12,662 [virtwho.init INFO] MainProcess(8794):MainThread @virtwho.py:parseOptions:637 - Using reporter_id='hp-z220-10.qe.lab.eng.nay.redhat.com'

================== ERROR Message ================
2016-04-01 11:33:12,665 [virtwho.init ERROR] MainProcess(8794):MainThread @config.py:__init__:341 - Configuration file .esx.conf.swp contains no section headers
=================================================

2016-04-01 11:33:12,665 [virtwho.init DEBUG] MainProcess(8794):MainThread @virtwho.py:__init__:125 - Using config named 'test-esx'
2016-04-01 11:33:12,665 [virtwho.init INFO] MainProcess(8794):MainThread @virtwho.py:main:729 - Using configuration "test-esx" ("esx" mode)
2016-04-01 11:33:12,683 [virtwho.main DEBUG] MainProcess(8796):MainThread @virtwho.py:run:231 - Starting infinite loop with 60 seconds interval
2016-04-01 11:33:12,811 [virtwho.test-esx DEBUG] Esx-1(8804):MainThread @virt.py:run:358 - Virt backend 'test-esx' started
2016-04-01 11:33:12,812 [virtwho.test-esx DEBUG] Esx-1(8804):MainThread @esx.py:_prepare:55 - Log into ESX
......

Actual results:
virt-who will read .esx.conf.swp file


Expected results:
virt-who shouldn't check .esx.conf.swp file


Additional info: