One more øMQ FFI fix that slipped through the cracks (#4188)
One more øMQ FFI fix that slipped through the cracks (#4188)

(Actually should be size_t, but gcc-lua downgraded that to the
pointed-to type, for... reasons?).

Fix #4187
poire-z/koreader,Frenzie/koreader,NiLuJe/koreader,Markismus/koreader,mwoz123/koreader,poire-z/koreader,NiLuJe/koreader,koreader/koreader,Hzj-jie/koreader,houqp/koreader,Frenzie/koreader,mihailim/koreader,pazos/koreader,koreader/koreader