Install script fails when a TEXMF path needs to be manually input.

[ashvinsrivatsa]

In pythontex_install_texlive.py at line 145, there's a check to see whether the path_choice variable is equal to the string "2". If kpsewhich is unavailable on the system, though, the script never hits the block at line 114 where path_choice is set. In this event, the script errors out:
NameError: name 'path_choice' is not defined

Presumably this could be fixed by adding a query to the user in the except: block at line 126 to find out whether the path they've manually inputted is a local path or not.