Restore defaults for combine and failonfail in openstack command

[1] added "override_locale: false" to the openstack command executions,
to respect the current locale. This had an unintended side effect,
since it changed the values for failonfail and combine to false in
that same execution, as described in [2].

We should ensure that openstack command failures are respected, so
this commit restores that behavior.

[1] - https://review.opendev.org/640997
[2] - https://github.com/puppetlabs/puppet/blob/master/lib/puppet/util/execution.rb#L139-L143

Change-Id: I55e587ea5c83338ae989aa56f1f379079eb02e08
(cherry picked from commit 726b06cdb4)

lib/puppet/provider/openstack.rb

@@ -45,7 +45,7 @@ class Puppet::Provider::Openstack < Puppet::Provider
     begin
       action = args[1]
       Timeout.timeout(command_timeout(action)) do
-        execute([command(:openstack_command)] + args, override_locale: false)
+        execute([command(:openstack_command)] + args, override_locale: false, failonfail: true, combine: true)
       end
     rescue Timeout::Error
       raise Puppet::ExecutionFailure, "Command: 'openstack #{args.inspect}' has been running for more than #{command_timeout(action)} seconds"