[torque-ls] Adding a required header needed for sorting

gcc requires the <algorithm> header for compiling std::sort. This issue
is not present when using Clang.

Change-Id: Ief7bfd6152754f71194c784b09dce39e357ddd5c
Reviewed-on: https://chromium-review.googlesource.com/c/1496280Reviewed-by: Simon Zünd <szuend@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59973}

src/torque/ls/message-handler.cc

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <algorithm>
 #include "src/torque/ls/message-handler.h"
 
 #include "src/torque/ls/globals.h"