ReaderFooter: fix quick browsing by tapping footer in flipping mode
ReaderFooter: fix quick browsing by tapping footer in flipping mode

Fixes #2649.

apletnev/koreader,Hzj-jie/koreader,mihailim/koreader,koreader/koreader,Frenzie/koreader,poire-z/koreader,mwoz123/koreader,robert00s/koreader,poire-z/koreader,Markismus/koreader,NiLuJe/koreader,lgeek/koreader,Frenzie/koreader,pazos/koreader,koreader/koreader,houqp/koreader,NiLuJe/koreader