Update @legoktm's email address

I am leaving the Wikimedia Foundation at the end of the year and won't
have access to that email address anymore. But I'll still be a member
of the MediaWiki community :-)

library/mediawiki

@@ -1,5 +1,5 @@
 Maintainers: David Barratt <[email protected]> (@davidbarratt),
-             Kunal Mehta <legoktm@wikimedia.org> (@legoktm),
+             Kunal Mehta <legoktm@debian.org> (@legoktm),
              addshore <[email protected]> (@addshore)
 GitRepo: https://github.com/wikimedia/mediawiki-docker.git
 GitCommit: 1795938062adeb7251b6a7180e0e40b975b5827a