* Update openstack inventory script to keep basic functionality (#43432)
re-applies commit 6667ec4474 which
fixed the plugin to the script so that it will work with current
ansible-inventory.
Also redirect stdout before dumping the ouptput, because not doing
so will cause JSON parse errors in some cases.
(cherry picked from commit fa45c44026)
* fixed the plugin to the script so that it will work with current