[fix, lang] ReaderGesture: toggle highlight action to cycle (#4809)
[fix, lang] ReaderGesture: toggle highlight action to cycle (#4809)

I overlooked this until I noticed it on Transifex today.

See https://github.com/koreader/koreader/pull/4791#discussion_r265546245

Also changing the internal name because for something that's only been in one or two nightlies there's no point in prematurely introducing legacy settings.
mihailim/koreader,Hzj-jie/koreader,Frenzie/koreader,poire-z/koreader,NiLuJe/koreader,koreader/koreader,Frenzie/koreader,mwoz123/koreader,pazos/koreader,poire-z/koreader,NiLuJe/koreader,houqp/koreader,koreader/koreader,Markismus/koreader