[kolnovel] Empty chapter:

All the kolnovel is empty and send back an error saying no readable content was found and when trying to download i get cannot convert the null value error

Same empty-chapter symptom as the lightnovelwp bottomnav break. Fix in progress in #2593 (focused template fix, now rewritten with a depth-tracked walk) with broader Arabic coverage in #2529. Linking for tracking — please see #2593 for verification.