text: Title: PuDB does not update for terminal size changes [Urwid issue]
  Body: When I resize the terminal (gnome-terminal) the view stays the same size although the window becomes bigger. After I move the cursor it becomes fullsize. It is weird as this only happens with pudb, not with other terminal programs ( I use ubuntu and i3 wm). 
  ![pudb](https://user-images.githubusercontent.com/15639804/104251131-54752b00-546f-11eb-8a6d-901793b48d67.png)
  
  _Originally posted by @makrobios in https://github.com/inducer/pudb/issues/410#issuecomment-758295335_