[doc] errata.mirantis.com is empty

[Serg Lystopad]

'Maintenance update' (MU) section at https://docs.mirantis.com/openstack/fuel/fuel-6.1/release-notes.html#maintenance-updates directs user to 'Applying patches'.
There are mentions of 'errata portal' (https://errata.mirantis.com/) which should be used to get exact procedures how to apply patches, but https://errata.mirantis.com/ is empty. I can not see any patch for any MU.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/6.1
Review: https://review.openstack.org/240579

[Olena Logvinova (ologvinova)]

The info is already updated in 7.0 and master branches, so this bug is does not affect Fuel for OpenStack 8.0 (https://docs.mirantis.com/openstack/fuel/fuel-7.0/operations.html#patching-ops)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/240579
Committed: https://git.openstack.org/cgit/openstack/fuel-docs/commit/?id=3c07677f8ce2a466e9b4a7d859513b3ba90808ae
Submitter: Jenkins
Branch: stable/6.1

commit 3c07677f8ce2a466e9b4a7d859513b3ba90808ae
Author: Olena Logvinova <email address hidden>
Date: Fri Oct 30 18:44:34 2015 +0200

    [Ops Guide] Applying patches: Remove mention of errata

    This patch:

    - replaces the errata links with MU links,
    - rephrases mentioning of errata with updated info where
      to find the documentation,
    - adds an intro sentence to the section,
    - corrects small grammar and rst markup mistakes.

    Change-Id: I08cb60d534391ff528a4632a44249754b1161d29
    Closes-Bug: #1511684