Unlike in other MediaWiki emails, creating an account by email and sending the new user a password that way results in the user also being sent only a protocol-relative url:
Someone created an account for your e-mail address on OTRS Wiki (<//otrs-wiki.wikimedia.org/w/index.php>) named "Isarra"...
There should be a http: in it like the urls in other emails have.
Version: unspecified
Severity: normal
Line 875 of SpecialUserlogin inside SpecialUserlogin::mailPasswordInternal.
Looks like $wgServer and $wgScript are used directly instead of using helper methods and using wfExpandUrl along with PROTO_CANONICAL.
No need to continue using global cruft when we have better interfaces for such things. Anything manually concatenating a $wg*Server with a path is way out of date.
I look forward to your changeset that cleans up the use of $wg*Server, $wgScript*, and so on throughout the whole codebase.