Lock icon from the OOjs UI MediaWiki lib.
<a href="https://phabricator.wikimedia.org/diffusion/GOJU/browse/master/AUTHORS.txt" class="extiw" title="phab:diffusion/GOJU/browse/master/AUTHORS.txt">phab:diffusion/GOJU/browse/master/AUTHORS.txt</a>
2018-03-21
<a href="https://phabricator.wikimedia.org/diffusion/GVED/browse/master/lib/oojs-ui/themes/wikimediaui/images/icons/" class="extiw" title="phab:diffusion/GVED/browse/master/lib/oojs-ui/themes/wikimediaui/images/icons/">../lib/oojs-ui/themes/wikimediaui/images/icons/</a>