bug#16028: 24.3.50; Latest build completely breaks my thumnail frames code

[Drew Adams]

> I consider such resizing insane because there's no guarantee that a
> toolkit will be able to cope with arbitrarily microsized scrollbars.

There's no guarantee against any fault of a window mgr.

The thumb-frm.el code wraps the shrinking/expanding in a condition-case, 
which restores the original size and other frame parameters in case of
error.  But for that, Emacs must be able to detect the error.