(KoStudyLastViewed.vue): fix is-active highlight when no active kanji
(KoStudyLastViewed.vue): fix is-active highlight when no active kanji

fabd/kanji-koohii,fabd/kanji-koohii,fabd/kanji-koohii,fabd/kanji-koohii,fabd/kanji-koohii,fabd/kanji-koohii