Fix account rc files creation for Swift users

Id02ebdfa5cb3f6c763293876c6bb031184ebd663 introduced a small
regression which makes the command x509-create-cert fail with
'ERROR (CommandError): Invalid OpenStack Nova credentials.' for
Swift users.

The handling of specific password for Swift users was introduced
in Ifb57a43aad439ffe041e98465719a8a8eceae544

Change-Id: I3f328b1358bad0bdf7056796eabfe846dd5bae3a
Merge "Fix account rc files creation for Swift users"
Merge branch 'master' of https://github.com/openstack-dev/devstack