(FlashcardReview): fix incorrect conditional for the onBeforeUnload event
(FlashcardReview): fix incorrect conditional for the onBeforeUnload event

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