Move jedi#_vim_exceptions before call to jedi#init_python
Move jedi#_vim_exceptions before call to jedi#init_python

It might be used during setup, in the case of errors and needs to be
defined then already.

FBruynbroeck/jedi-vim,aliev/jedi-vim,jmartiuk5/jedi-vim,clavery/jedi-vim,maxamillion/jedi-vim,wilywampa/jedi-vim,pze/jedi-vim,davidhalter/jedi-vim,itchyny/jedi-vim,genzj/jedi-vim