Reproduce when installing a new mw, at one step the list of authors of MW are shown ending with 'others' pointing to an invalid link.

Call to SpecialVersion::getCopyrightAndAuthorList() in WebInstallerPage.php leads to generation of invalid link using
'[[Special:Version/Credits|' .

			wfMessage( 'version-poweredby-others' )->text() .
			']]'

as the wiki is not even installed. Instead it should point to a source which already exists, maybe mw.org/Special:Version ?

Version: 1.21.x
Severity: minor