Don't break refresh if a flavor couldn't be found

[mansam]

This PR prevents refresh from failing when a flavor's access list couldn't be retrieved due to a network issue or a nonexistent flavor. Fixes:

https://bugzilla.redhat.com/show_bug.cgi?id=1460683

[miq-bot]

Checked commits mansam/manageiq-providers-openstack@1bcb0ae~...83b67c4 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
2 files checked, 0 offenses detected
Everything looks fine. ⭐

[tzumainn]

Looks good!

[simaishi]

app/models/manageiq/providers/openstack/inventory/collector/cloud_manager.rb doesn't exist in Euwe branch, so backported app/models/manageiq/providers/openstack/refresh_parser_common/flavors.rb only.

Euwe backport (to manageiq repo) details:

$ git log -1
commit 98a79bd52b15a73d404468703dc775ca1d8c32db
Author: tzumainn <tzumainn@redhat.com>
Date:   Mon Jul 24 09:17:56 2017 -0400

    Merge pull request #69 from mansam/dont-break-refresh-if-flavor-is-missing
    
    Don't break refresh if a flavor couldn't be found
    (cherry picked from commit f3ba0ffd038dea2d017d66e994b37a904450270f)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1476279

[simaishi]

Same for Fine branch - backported app/models/manageiq/providers/openstack/refresh_parser_common/flavors.rb only.

Fine backport (to manageiq repo) details:

$ git log -1
commit 5534ac2906102a4a05f34e6bad1a64a63a0cbf8e
Author: tzumainn <tzumainn@redhat.com>
Date:   Mon Jul 24 09:17:56 2017 -0400

    Merge pull request #69 from mansam/dont-break-refresh-if-flavor-is-missing
    
    Don't break refresh if a flavor couldn't be found
    (cherry picked from commit f3ba0ffd038dea2d017d66e994b37a904450270f)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1479978