Rust: Components field ignores intention of profile field

[dcbaker]

I've set the the profile option to minimal, as I only want cargo, rustc, and rust-std installed. I then have to set components to "cargo,rustc,rust-std", as otherwise I still end up with clippy, rust-fmt and rust-analyzer installed. Setting components to "" results in the same behavior, and setting it to null causes an error.

It would be nice to allow components to be either "" or null, to signal that the profile is enough and I don't want any additional components installed.