[fix] kobo/nickel_conf: Remove redundant 'return nil'
[fix] kobo/nickel_conf: Remove redundant 'return nil'

Hzj-jie/koreader,mwoz123/koreader,koreader/koreader,houqp/koreader,koreader/koreader,mihailim/koreader,Frenzie/koreader,Frenzie/koreader,pazos/koreader,NiLuJe/koreader,poire-z/koreader,lgeek/koreader,Markismus/koreader,poire-z/koreader,NiLuJe/koreader