The output for [[m:Special:GlobalBlockList]] gives hard output of an http: link of the person doing the block rather than the preferred of protocol relative. The protocol of the IP address being blocked is correct.
Looking at the line item
https://meta.wikimedia.org/wiki/MediaWiki:Globalblocking-list-blockitem
shows that this is not customisable onwiki, so presumably it just a little tweak in the extension.
Version: unspecified
Severity: normal