[PATCH] models: Fix HeaderParser import on python 2.4

[Sabuj Pattanayek]

>> I applied the patch, actually ran git pull
>
> The git repo does not include this change, you'll need to apply the patch
> manually.

Ahh, I took a quick glance at the changes in models.py after git pull,
saw "Python 2.4 compatibility" and thought that you had merged it .
Seems like the git pull was basically just missing the one line :

from email.Parser import HeaderParser

After adding that line, the mbox link now works .