Pop password from os_user params

The password param conflicts with os-client-config's password grabbing.
The rest of the params really probably should also be popped - but
keeping this just to password for now. Will follow up with a change that
does an audit of all the os_ modules

This patch was previously contributed by @emonty to the former
ansible-modules-core repo however since the merge, it was closed
and not completed.  This patch includes the necessary changes cleaned
up to work with the latest release of Ansible.  This has been
tested to work internally

lib/ansible/modules/cloud/openstack/os_user.py

@@ -201,7 +201,7 @@ def main():
         module.fail_json(msg='shade is required for this module')
 
     name = module.params['name']
-    password = module.params['password']
+    password = module.params.pop('password')
     email = module.params['email']
     default_project = module.params['default_project']
     domain = module.params['domain']