message: Update specifying-dependencies.md
diff: @@ -465,11 +465,8 @@ If you want to know which cfg targets are available on your platform, run
  `rustc --print=cfg` from the command line. If you want to know which `cfg`
  targets are available for another platform, such as 64-bit Windows,
  run `rustc --print=cfg --target=x86_64-pc-windows-msvc`.
  -If you want to know which cfg targets are used by the release profile,
  -add the `-O` parameter.
  -This same set of values is used throughout the build for all crates in your project,
  -so, unlike in your Rust source code,
  +Unlike in your Rust source code,
  you cannot use `[target.'cfg(feature = "my_crate")'.dependencies]` to add
  dependencies based on optional crate features.
  Use [the `[features]` section](manifest.md#the-features-section) instead.
  