Do not pollute with global variables

[itchyny]

I found three global variables you might not intend them to be. The variables e, l1, l2 at https://github.com/davidhalter/jedi-vim/blob/master/after/syntax/python.vim#L4 are global variables. When we open a python file and you confirm the leak with :echo [e, l1, l2]. Make them script local or put them into a function.

[davidhalter]

Yes, we should fix that. What's the best fix? s:? If you want you can do a PR.

[itchyny]

Yup, add s: to all the occurrence.