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/IpmbSensor.hpp b/src/IpmbSensor.hpp
index 6467b57..bf94509 100644
--- a/src/IpmbSensor.hpp
+++ b/src/IpmbSensor.hpp
@@ -83,7 +83,7 @@
     public std::enable_shared_from_this<IpmbSensor>
 {
     IpmbSensor(std::shared_ptr<sdbusplus::asio::connection>& conn,
-               boost::asio::io_service& io, const std::string& name,
+               boost::asio::io_context& io, const std::string& name,
                const std::string& sensorConfiguration,
                sdbusplus::asio::object_server& objectServer,
                std::vector<thresholds::Threshold>&& thresholdData,