update k2pdfopt to version 1.66
update k2pdfopt to version 1.66

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