Change io_service to io_context

This was renamed a while back in boost to be compliant with the
std::executors proposal.

Change-Id: Ib56544a0a7478990d18fe9e0bbbd8db1e52fa5b8
Signed-off-by: Ed Tanous <edtanous@google.com>
diff --git a/src/ExitAirTempSensor.cpp b/src/ExitAirTempSensor.cpp
index d126def..8808ac8 100644
--- a/src/ExitAirTempSensor.cpp
+++ b/src/ExitAirTempSensor.cpp
@@ -931,7 +931,7 @@
 int main()
 {
 
-    boost::asio::io_service io;
+    boost::asio::io_context io;
     auto systemBus = std::make_shared<sdbusplus::asio::connection>(io);
     sdbusplus::asio::object_server objectServer(systemBus, true);
     objectServer.add_manager("/xyz/openbmc_project/sensors");