Fix cargo build warnings on windows

[gabbifish]

These warnings occur on windows when cargo build runs:

warning: unused import: `std::fs::File`
 --> src\commands\config.rs:3:5
  |
3 | use std::fs::File;
  |     ^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: unused import: `std::path::PathBuf`
 --> src\commands\config.rs:6:5
  |
6 | use std::path::PathBuf;
  |    

let's fix this :)