Version 1.2.x changes behaviour

[vmx]

I've a problem with upgrading from 1.1.3 to version 1.2.1. Here are the steps to reproduce the problem.

git clone https://github.com/multiformats/rust-multihash.git --branch v0.16.3
cd rust-multihash
cargo build
cargo update --package proc-macro-crate
cargo build

The build fails, due to crate_name() returning Ok(FoundCrate::Name("multihash")) instead of Ok(FoundCrate::Itself) (https://github.com/multiformats/rust-multihash/blob/v0.16.3/derive/src/utils.rs#L8-L11).

You can see the difference in the output via cargo expand multihash_impl.

[vmx]

Thanks a lot for the fix, it fixes my issue!

[bkchr]

NP! I tested it with your repo :D