fix refactor bug: invalidate update_regions_func
fix refactor bug: invalidate update_regions_func

NiLuJe/koreader,chihyang/koreader,NickSavage/koreader,ashang/koreader,NiLuJe/koreader,frankyifei/koreader,Hzj-jie/koreader,pazos/koreader,Frenzie/koreader,apletnev/koreader,noname007/koreader,ashhher3/koreader,poire-z/koreader,houqp/koreader,koreader/koreader,robert00s/koreader,lgeek/koreader,mwoz123/koreader,mihailim/koreader,Frenzie/koreader,chrox/koreader,Markismus/koreader,poire-z/koreader,koreader/koreader