don't crash in antique browsers which don't support `querySelector`; simile of commit SHA-1: 6dce1e0fd935e0a625cb5096950770b03c80d5f8
don't crash in antique browsers which don't support `querySelector`; simile of commit SHA-1: 6dce1e0fd935e0a625cb5096950770b03c80d5f8

* Do not break on browsers not supporting querySelector()

Don't let NProgress breaks and skip side feature on browsers not supporting Selectors API.

GerHobbelt/nprogress,GerHobbelt/nprogress,GerHobbelt/nprogress