Fix comment (#2555)

Author: mtharrison

cli/Cargo.toml

@@ -1,6 +1,6 @@
 # Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 # Dummy package info required by `cargo fetch`.
-# Use tools/sync_third_party.py to install deps after editing this file.
+# Use tools/sync_rust_crates.py to install deps after editing this file.
 # Deno does not build with cargo. Deno uses a build system called gn.
 # See build_extra/rust/BUILD.gn for the manually built configuration of rust
 # crates.