handle missing udev process

OBS-URL: https://build.opensuse.org/package/show/Cloud:Tools/cloud-init?expand=0&rev=239

cloud-init-wait-for-net.patch

@@ -1,12 +1,15 @@
 --- cloudinit/sources/helpers/openstack.py.orig
 +++ cloudinit/sources/helpers/openstack.py
-@@ -736,7 +736,11 @@ def convert_net_json(network_json=None,
+@@ -736,7 +736,14 @@ def convert_net_json(network_json=None,
              if not mac:
                  raise ValueError("No mac_address or name entry for %s" % d)
              if mac not in known_macs:
 -                raise ValueError("Unable to find a system nic for %s" % d)
 +                # Let's give udev a chance to catch up
-+                util.udevadm_settle()
++                try:
++                    util.udevadm_settle()
++                exceptsubp.ProcessExecutionError:
++                    pass
 +                known_macs = net.get_interfaces_by_mac()
 +                if mac not in known_macs:
 +                    raise ValueError("Unable to find a system nic for %s" % d)