remove unused asio/sd_event.hpp include

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I7b0dcb665c630cbe52b2835a9e10a8cce2d70c56
diff --git a/sd_event_loop.cpp b/sd_event_loop.cpp
index c00b146..4d55977 100644
--- a/sd_event_loop.cpp
+++ b/sd_event_loop.cpp
@@ -12,7 +12,6 @@
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/signal_set.hpp>
 #include <phosphor-logging/lg2.hpp>
-#include <sdbusplus/asio/sd_event.hpp>
 #include <user_channel/channel_layer.hpp>
 
 namespace eventloop