Mod. #! for systems with py3 as default in $PATH

Hey! I saw your script on reddit, and couldn't help but decide to take it and bend it to my own nefarious needs.

A minor, minor alteration - xmobar-mtgox does not currently work on distros that have Python 3 as their default (such as Arch). Seeing as systems with Python 2 installed /should/ have python2 being a guaranteed Python 2 binary, I felt this single-character change might make the script a bit more robust.

But seriously, Python 3. And also Arch.

Did I mention Arch?