Don't assume NIC IP configuration has subnet

[djberg96]

Not all IP configurations for all NIC's will have a subnet. If it doesn't, the refresh parser for the NetworkManager will break. This fixes that.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1494143

[miq-bot]

Checked commit https://github.com/djberg96/manageiq-providers-azure/commit/07ff99f9a8cec7d608f5de9d0d471233a1afdba8 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
1 file checked, 0 offenses detected
Everything looks fine. 🍰

[simaishi]

Fine backport details:

$ git log -1
commit c9dab7134019cd139749816119b09e5c3e08ba27
Author: Bronagh Sorota <bsorota@redhat.com>
Date:   Mon Sep 25 09:38:45 2017 -0400

    Merge pull request #132 from djberg96/nic_subnets
    
    Don't assume NIC IP configuration has subnet
    (cherry picked from commit 4fef0d85222c284a68c29a024e770e4ff1f3f960)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1496931

[djberg96]

@simaishi Needs a Euwe backport, too, please.

[simaishi]

@djberg96 I need to check if this is a blocker for the upcoming Euwe release or not, as this wasn't on the blocker list and I can only backport for approved blockers.

[simaishi]

Euwe backport (to manageiq repo) details:

$ git log -1
commit 656a62e790184bddc4213a7dd9247e67da81b1ec
Author: Bronagh Sorota <bsorota@redhat.com>
Date:   Mon Sep 25 09:38:45 2017 -0400

    Merge pull request #132 from djberg96/nic_subnets
    
    Don't assume NIC IP configuration has subnet
    (cherry picked from commit 4fef0d85222c284a68c29a024e770e4ff1f3f960)
    
    Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1468604