Bump HB to v2.3.1
Bump HB to v2.3.1

NiLuJe/koreader-base,Frenzie/koreader-base,NiLuJe/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,koreader/koreader-base,NiLuJe/koreader-base,Frenzie/koreader-base,houqp/koreader-base,koreader/koreader-base,koreader/koreader-base,Frenzie/koreader-base,Frenzie/koreader-base,houqp/koreader-base,houqp/koreader-base,houqp/koreader-base