pan.git not displaying jpegs in body pane

Hi Heinrich :)

I just built your latest git (29250f5) and find that any posts with 
attached jpegs display in the body pane as raw undecoded text, i.e.
yenc or whatever, instead of as a picture.

If I 'Save' the jpeg to disk, though, everything works as expected.

I haven't yet bisected/debugged the problem because I'm guessing you
will already know what caused the change, but I'm happy to pursue
it further if you like.

I'm assuming that this change in behavior is not intended, right?

Thanks!