uimanager: fix crash on crash....
uimanager: fix crash on crash....

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