bug#24317: 25.1.50; image-dired-rotate-original: regexp doesn't match .jpeg suffix

[Tino Calancha]

> I understand why we need to fix a typo in the regexp (which the log
> entry doesn't even mention, btw), but what's the rationale for making
> it a defvar?
I made a defvar because it was used in 2 functions: only one show the 
typo.
Do you prefer just the simple 1-line fix? (ie., just correct the typo)