[PATCH 1 of 3] rust: update Cargo.lock to include @generated comment

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1560562503 -32400
#      Sat Jun 15 10:35:03 2019 +0900
# Node ID 1e87fad0e1c119b7d2d88f09e9823581cd69dbb8
# Parent  ed9a995640518fd7fa893817f0250f4d319a4b40
rust: update Cargo.lock to include @generated comment

cargo 1.34.0 of Debian sid inserts this comment, and I'm tired of reverting
the change every time I do make local.

https://github.com/rust-lang/cargo/commit/bd0e4a08471b8bc7957829b4fd294b8985d4fa2d

diff --git a/rust/Cargo.lock b/rust/Cargo.lock
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
 version = "0.6.9"