fix for rotated document to file manager transition: do a refresh

fixes part 2 of #1333

frontend/apps/filemanager/filemanager.lua

@@ -199,6 +199,7 @@ end
 function FileManager:restoreScreenMode()
     local screen_mode = G_reader_settings:readSetting("fm_screen_mode")
     Screen:setScreenMode(screen_mode or "portrait")
+    UIManager:setDirty(self, "full")
 end
 
 function FileManager:showFiles(path)