[swarm] Links aren't available during replacement of cluster repositories

Detailed bug description:
Found on CI:
https://product-ci.infra.mirantis.net/job/9.x.system_test.ubuntu.plugins.thread_separate_haproxy/15/consoleFull

Test: Deploy HA environment with separate Haproxy
Test Group: separate_haproxy

Steps to reproduce:
        1. Revert snapshot with ready master node
        2. Copy and install external-lb and detach-haproxy plugins
        3. Bootstrap 3 slaves from default nodegroup
        4. Create cluster with Neutron VXLAN and custom nodegroups
        5. Run 'fuel-mirror' to replace cluster repositories
           with local mirrors
Expected results:
 All links are available, cluster repositories are replaced
Actual result:
 Some links aren't available, cluster repositories aren't replaced, test is failed
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/packetary/library/connections.py", line 214, in open_stream
    return self.opener.open(request)
  File "/usr/lib64/python2.7/urllib2.py", line 431, in open
    response = self._open(req, data)
  File "/usr/lib64/python2.7/urllib2.py", line 449, in _open
    '_open', req)
  File "/usr/lib64/python2.7/urllib2.py", line 409, in _call_chain
    result = func(*args)
  File "/usr/lib64/python2.7/urllib2.py", line 1244, in http_open
    return self.do_open(httplib.HTTPConnection, req)
  File "/usr/lib64/python2.7/urllib2.py", line 1214, in do_open
    raise URLError(err)
URLError: <urlopen error [Errno -2] Name or service not known>
Failed to open url - http://mirror.fuel-infra.org/mos-repos/ubuntu/9.0/pool/main/p/python-os-brick/os-brick-common_1.2.0-4~u14.04+mos1_all.deb: <urlopen error [Errno -2] Name or service not known>. retries left - 1.

Description of the environment:
9.1 snapshot #81

FUEL_QA_COMMIT=bfb750898b0f5ef196eb0c8a295cc29279487ade
UBUNTU_MIRROR_ID=ubuntu-2016-07-31-170655
CENTOS_MIRROR_ID=centos-7.2.1511-2016-05-31-083834
MOS_UBUNTU_MIRROR_ID=9.0-2016-08-01-154321
MOS_CENTOS_OS_MIRROR_ID=os-2016-06-23-135731
MOS_CENTOS_PROPOSED_MIRROR_ID=proposed-2016-08-01-154321
MOS_CENTOS_UPDATES_MIRROR_ID=updates-2016-06-23-135916
MOS_CENTOS_HOLDBACK_MIRROR_ID=holdback-2016-06-23-140047
MOS_CENTOS_HOTFIX_MIRROR_ID=hotfix-2016-07-18-162958
MOS_CENTOS_SECURITY_MIRROR_ID=security-2016-06-23-140002

https://drive.google.com/a/mirantis.com/file/d/0Bz15vbpS5ZPNQ3BqdWZjeDA1bGs/view?usp=sharing