fix Menu widget initialization on inheritance bug in filechooser
fix Menu widget initialization on inheritance bug in filechooser

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