Revert "Register company-go with company-backends"
Revert "Register company-go with company-backends"

This reverts commit 6f18981971171520cc9ea522837916987187508f.

This change caused issues with some company setups. Users should
configure the backend in init scripts.

mdempsky/gocode,mdempsky/gocode,nsf/gocode,nsf/gocode,nsf/gocode,nsf/gocode,mdempsky/gocode