Fix a few edge cases crashes and issues (#4334)

- ReaderConfig does not need to call again self:initGesListener() on
  screen rotation/resize, as it uses the TouchZone infrastructure
  that deals itself with rotation. So, it was adding new gestures
  that were overriding tap on footer and preventing it from working.
- ReaderFooter: fix refresh area (which was too small when toggling
  from hidden to visible)
- ReaderToc: fix crash when showing TOC in scroll mode after rotation
- Menu: fix crash when no onReturn defined (could happen when tap on
  bottom left corner when showing an empty TOC)

frontend/apps/reader/modules/readerconfig.lua

@@ -93,9 +93,6 @@ function ReaderConfig:onSwipeShowConfigMenu(ges)
 end
 
 function ReaderConfig:onSetDimensions(dimen)
-    if Device:isTouchDevice() then
-        self:initGesListener()
-    end
     -- since we cannot redraw config_dialog with new size, we close
     -- the old one on screen size change
     if self.config_dialog then