Remove deprecated method insertArticleLink() from class ChangeList

Remove deprecated method insertArticleLink() from class ChangeList

This method was deprecated in MediaWiki 1.27 and in MW 1.26, an alternative
method was introduced (getArticleLink). Per the code search tool here:
https://codesearch.wmflabs.org/search/?q=insertArticleLink%5C(&i=nope&files=&repos=,
only SimpleChanges and RecentActivityFeed extensions still use this method and
patches have been made to stop the use of these deprecated methods, see;
~ Ia80496c02ee5d0cb7bf9bdb1b336ea2699325d4c (RecentActivityFeed extension)
~ I5a9359f107da6a92b5f52e58879b540480ed2443 (SimpleChanges extension)

Once the above patches are merged, this patch can be reviewed and merged
as there will no longer be any usage of the deprecated method per code search
tool.

Change-Id: I166a7e5af7d8d3df60208583b6ce002bf65305a6