[chore] Proper plurals in CoverBrowser processing (#6483)
[chore] Proper plurals in CoverBrowser processing (#6483)

As reported by @lescheck on Weblate

> I think this should be in plural form (because of second line)
Markismus/koreader,poire-z/koreader,pazos/koreader,Frenzie/koreader,mwoz123/koreader,Hzj-jie/koreader,NiLuJe/koreader,koreader/koreader,poire-z/koreader,koreader/koreader,Frenzie/koreader,NiLuJe/koreader