Add Yusuke Endoh's mastodon handle in winners.csv

.. I haven't changed the entries as there are of course a lot! That can
come another time .. or not :-)

tmp/winners.csv

@@ -192,6 +192,6 @@ Vern Paxson,Vern_Paxson,null,null,vern@ee.lbl.gov,null,null,null
 Vincent Weaver,Vincent_Weaver,http://www.deater.net/weave/,null,vince@deater.net,US,null,null
 Volker Diels-Grabsch,Volker_Diels-Grabsch,https://njh.eu,null,v@njh.eu,null,null,null
 Walter Bright,Walter_Bright,http://www.walterbright.com/,null,emperor@classicempire.com,null,null,null
-Yusuke Endoh,Yusuke_Endoh,null,null,mame@ruby-lang.org,null,@mametter,null
+Yusuke Endoh,Yusuke_Endoh,null,null,mame@ruby-lang.org,null,@mame@ruby.social,null
 Yves-Marie Morgan,Yves-Marie_Morgan,null,null,null,null,null,null
 tsoj ,_tsoj,https://gitlab.com/tsoj,null,tsoj.tsoj@gmx.de,null,null,null