Fixes build on ~arch system, patch from upstream, to be dropped for 0.47

From 10daadefbea1f62a818c339dc7f3d69a858bc8a6 Mon Sep 17 00:00:00 2001
From: elsid <elsid.mail@gmail.com>
Date: Thu, 30 Apr 2020 21:57:22 +0200
Subject: [PATCH] Add missing include

diff --git a/components/detournavigator/offmeshconnectionsmanager.hpp b/components/detournavigator/offmeshconnectionsmanager.hpp
index 30d7976aec..155ce32963 100644
--- a/components/detournavigator/offmeshconnectionsmanager.hpp
+++ b/components/detournavigator/offmeshconnectionsmanager.hpp
@@ -13,6 +13,7 @@
 
 #include <boost/optional.hpp>
 
+#include <algorithm>
 #include <map>
 #include <mutex>
 #include <unordered_map>