Fix Nika's entry in the mailmap

Author: Manishearth

.mailmap

@@ -186,6 +186,7 @@ Neil Pankey <npankey@gmail.com> <neil@wire.im>
 Nick Platt <platt.nicholas@gmail.com>
 Nicole Mazzuca <npmazzuca@gmail.com>
 Nif Ward <nif.ward@gmail.com>
+Nika Layzell <michael@thelayzells.com>
 Oliver Middleton <olliemail27@gmail.com> <ollie27@users.noreply.github.com>
 Oliver Scherer <oliver.schneider@kit.edu> <git-spam-no-reply9815368754983@oli-obk.de>
 Oliver Scherer <oliver.schneider@kit.edu> <git-spam9815368754983@oli-obk.de>