Fix title and anchor of network proxies section
@@ -25,7 +25,7 @@ And it runs on all platforms Rust supports, including Windows.
* [Cross-compilation](#cross-compilation)
* [Working with Rust on Windows](#working-with-rust-on-windows)
* [Working with custom toolchains](#working-with-custom-toolchains-and-local-builds)
-* [Working with HTTP proxies](#working-with-http-proxies)
+* [Working with network proxies](#working-with-network-proxies)
* [Examples](#examples)
* [Environment variables](#environment-variables)
* [Other installation methods](#other-installation-methods)
