see: https://bugs.gentoo.org/946571

From: Bill Prendergast <dek.devel@baisenvar.info>

Fix build with >=dev-libs/boost-1.87
 required for for net-im/swift boost-1.87 patch

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -109,6 +109,7 @@ if(${Boost_VERSION} GREATER 104999)
 	add_definitions(-DBOOST_FILESYSTEM_VERSION=3)
 endif()
 add_definitions(-DBOOST_BIND_GLOBAL_PLACEHOLDERS)
+add_definitions(-DBOOST_VERSION=${Boost_VERSION})
 
 # FIND POPT
 if(NOT WIN32)
--- a/include/Swiften/Network/DummyConnectionServer.h
+++ b/include/Swiften/Network/DummyConnectionServer.h
@@ -6,7 +6,11 @@
 
 #pragma once
 
+#if BOOST_VERSION < 108600
 #include <boost/asio/io_service.hpp>
+#else
+#include <boost/asio/io_context.hpp>
+#endif
 #include <boost/asio/ip/tcp.hpp>
 #include <boost/enable_shared_from_this.hpp>
 #include <boost/signals2.hpp>
--- a/include/Swiften/Network/DummyConnectionServerFactory.h
+++ b/include/Swiften/Network/DummyConnectionServerFactory.h
@@ -6,7 +6,11 @@
 
 #pragma once
 
+#if BOOST_VERSION < 108600
 #include <boost/asio/io_service.hpp>
+#else
+#include <boost/asio/io_context.hpp>
+#endif
 
 #include <Swiften/Network/ConnectionServerFactory.h>
 #include <Swiften/Network/DummyConnectionServer.h>