Follow-on from autocomplete and gallery.panel.js revisions.

(9345dde83e1f092a9309c45282dc21e3fd408875, d632ef3e50252d388c272cacd29e8cc6e4949cec, fd012276cbf03cc1dc7b8da10aac5cc6f26326c6)
- revised xss_data.txt golden file (no new cases).
- escaped translated string in admin_users.html.php (would have otherwise been a new case in xss_data.txt).