Update PhabricatorKoreanTranslation.php
Update PhabricatorKoreanTranslation.php

* see readme.md ("작업" -> "행위")
* solved concern: see https://issue.librewiki.net/rTR084769b67965ddaac1995357e7789bbedc20ed87
librewiki/phabricator-korean-i18n,hwangjy9/phabricator-korean-i18n,librewiki/phabricator-korean-i18n,hwangjy9/phabricator-korean-i18n