update crengine: fix <code> element
update crengine: fix <code> element

(needs https://github.com/koreader/crengine/pull/5)

NiLuJe/koreader-base,Frenzie/koreader-base,apletnev/koreader-base,koreader/koreader-base,houqp/koreader-base,koreader/koreader-base,frankyifei/koreader-base,apletnev/koreader-base,Frenzie/koreader-base,frankyifei/koreader-base,Hzj-jie/koreader-base,Frenzie/koreader-base,koreader/koreader-base,apletnev/koreader-base,NiLuJe/koreader-base,houqp/koreader-base,Hzj-jie/koreader-base,frankyifei/koreader-base,NiLuJe/koreader-base,NiLuJe/koreader-base,houqp/koreader-base,frankyifei/koreader-base,apletnev/koreader-base,Hzj-jie/koreader-base,Frenzie/koreader-base,koreader/koreader-base,houqp/koreader-base,Hzj-jie/koreader-base