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/PSUSensor.hpp b/src/PSUSensor.hpp
index 379b9d9..49e181e 100644
--- a/src/PSUSensor.hpp
+++ b/src/PSUSensor.hpp
@@ -18,7 +18,7 @@
     PSUSensor(const std::string& path, const std::string& objectType,
               sdbusplus::asio::object_server& objectServer,
               std::shared_ptr<sdbusplus::asio::connection>& conn,
-              boost::asio::io_service& io, const std::string& sensorName,
+              boost::asio::io_context& io, const std::string& sensorName,
               std::vector<thresholds::Threshold>&& thresholds,
               const std::string& sensorConfiguration,
               const PowerState& powerState, const std::string& sensorUnits,