[QA][CI] replace_fuel_nailgun_rpm() fails to update the nailgun package

[Roman Podoliaka]

A few builds of 10.0-pkg-mos-systest-ubuntu-xenial:

https://packaging-ci.infra.mirantis.net/view/MOS%2010.0/job/10.0-pkg-mos-systest-ubuntu-xenial/409/
https://packaging-ci.infra.mirantis.net/view/MOS%2010.0/job/10.0-pkg-mos-systest-ubuntu-xenial/406/

failed with the following error when trying to update the nailgun package:

2017-01-05 17:30:38 - INFO utils.py:192 -- Delete package fuel-nailgun-10.0.0-1.mos9031.noarch
2017-01-05 17:30:39 - INFO utils.py:196 -- Install package fuel-nailgun-10.0.0-1.mos9023.git.c569b98.noarch
fuel-nailgun-10.0.0-1.mos9030.git.37ba843.noarch
2017-01-05 17:30:41 - ERROR log_helpers.py:218 -- Failed:
'generate_logs'(
    'self'=[<class 'fuelweb_test.models.nailgun_client.NailgunClient'>(0x7f9ee309e6d0), url:None],
)
Traceback (most recent call last):
  File "/home/jenkins/workspace/10.0-pkg-mos-systest-ubuntu-xenial/fuel-qa/core/helpers/log_helpers.py", line 204, in wrapped
    result = func(*args, **kwargs)
  File "/home/jenkins/workspace/10.0-pkg-mos-systest-ubuntu-xenial/fuel-qa/fuelweb_test/models/nailgun_client.py", line 378, in generate_logs
    return self._put(url="/logs/package").json()
  File "/home/jenkins/workspace/10.0-pkg-mos-systest-ubuntu-xenial/fuel-qa/fuelweb_test/models/nailgun_client.py", line 61, in _put
    return self.session.put(url=url, connect_retries=1, **kwargs)
  File "/home/jenkins/venv-nailgun-tests-2.9/local/lib/python2.7/site-packages/keystoneauth1/session.py", line 726, in put
    return self.request(url, 'PUT', **kwargs)
  File "/home/jenkins/venv-nailgun-tests-2.9/local/lib/python2.7/site-packages/positional/__init__.py", line 101, in inner
    return wrapped(*args, **kwargs)
  File "/home/jenkins/venv-nailgun-tests-2.9/local/lib/python2.7/site-packages/keystoneauth1/session.py", line 607, in request
    raise exceptions.from_response(resp, method, url)
BadGateway: Bad Gateway (HTTP 502)

It looks like the name of the new package is produced incorrectly here (due to using of a wildcard * and having multiple files in the directory):

https://github.com/openstack/fuel-qa/blob/master/gates_tests/helpers/utils.py#L150

specifically it becomes "fuel-nailgun-10.0.0-1.mos9023.git.c569b98.noarch\nfuel-nailgun-10.0.0-1.mos9030.git.37ba843.noarch"

and, thus, nailgun is removed, but never installed again.