MediaWiki shows padlock icons next to HTTPS links because a plone developer back in 2003 thought they were cute. Nowadays more and more websites are going HTTPS entirely, and this link decoration is unnecessary clutter. I discussed this here, to figure out why this happens and how to switch them off on my own wikis: https://www.mediawiki.org/wiki/Thread:Project:Support_desk/Padlock_icons_on_HTTPS_links._Why%3F_and_how_to_switch_off%3F ...but with this bug I humbly suggest that the default should maybe be changed.
Steps to Reproduce:
put a HTTPS URL on a wiki page e.g. https://twitter.com/harry_wood and preview/save the page to see how it renders
On the default mediawiki vector skin you get a small yellow padlock icon to the right of the link. This is quite visually cluttering, making for unnecessarily ugly wiki pages (and with no security advantage that I can see)
The normal 'external link' icon would be better. Or at least we could phase-out the padlock, moving to a more subtle blue padlock as used on wikimedia sites
Reproducible: Didn't try
T61893: Remove padlock icon from links in Wikimedia Bugzilla installation
T32682: Link icon inconsistencies when using protocol relative URLs