v0.10.3 rust docs are broken

[mvines]

After fixing #1700, rust docs are still broken :-/

error: failed to run custom build command for `solana v0.10.3`
process didn't exit successfully: `/home/cratesfyi/cratesfyi/debug/build/solana-724c5dad4bc82ad6/build-script-build` (exit code: 101)
--- stdout
cargo:rerun-if-changed=build.rs

--- stderr
thread 'main' panicked at 'Unable to create target/perf-libs: Os { code: 2, kind: NotFound, message: "No such file or directory" }', /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/solana-0.10.3/build.rs:13:13
note: Run with `RUST_BACKTRACE=1` for a backtrace.

warning: build failed, waiting for other jobs to finish...
thread 'main' panicked at 'ErrorMessage {
    msg: "build failed"
}', src/bin/cratesfyi.rs:142:13
note: Run with `RUST_BACKTRACE=1` for a backtrace.

See https://docs.rs/crate/solana/0.10.3/builds/126226

[mvines]

🎉 https://docs.rs/solana/0.10.4/solana/