docs(client): correct malformed reference link in set_interface (#254)

Author: magurotuna

src/client/legacy/connect/http.rs

@@ -397,7 +397,7 @@ impl<R> HttpConnector<R> {
     /// - macOS, iOS, visionOS, watchOS, and tvOS
     ///
     /// [VRF]: https://www.kernel.org/doc/Documentation/networking/vrf.txt
-    /// [`man 7 socket`] https://man7.org/linux/man-pages/man7/socket.7.html
+    /// [`man 7 socket`]: https://man7.org/linux/man-pages/man7/socket.7.html
     /// [`man 7p ip`]: https://docs.oracle.com/cd/E86824_01/html/E54777/ip-7p.html
     #[cfg(any(
         target_os = "android",