Fix flipping mode refreshes

Don't do regional footer refreshes when we're in flipping mode.
There's probably a more elegant/correct way to handle this, but this
does the job ;).
Fix #1140

frontend/apps/reader/modules/readerfooter.lua

@@ -267,21 +267,21 @@ function ReaderFooter:onTapFooter(arg, ges)
             self.mode = 0
         end
         self:applyFooterMode()
+        local region = Geom:new{
+            x = 0,
+            y = Screen:getHeight() - self.height,
+            w = Screen:getWidth(),
+            h = self.height
+        }
+        UIManager.update_regions_func = function()
+            return {region}
+        end
     end
     if self.pageno then
         self:updateFooterPage()
     else
         self:updateFooterPos()
     end
-    local region = Geom:new{
-        x = 0,
-        y = Screen:getHeight() - self.height,
-        w = Screen:getWidth(),
-        h = self.height
-    }
-    UIManager.update_regions_func = function()
-       return {region}
-    end
     UIManager:setDirty(self.view.dialog, "partial")
     G_reader_settings:saveSetting("reader_footer_mode", self.mode)
     return true