ag_literal.py: remove unused import (Flake8 F401)
ag_literal.py: remove unused import (Flake8 F401)

https://github.com/nvbn/thefuck/pull/561#discussion_r81892699

Clpsplug/thefuck,Clpsplug/thefuck,scorphus/thefuck,scorphus/thefuck,SimenB/thefuck,mlk/thefuck,mlk/thefuck,nvbn/thefuck,nvbn/thefuck,SimenB/thefuck