PubSub: Add the pubsub_ethernet.h if required in the IOP example

examples/pubsub/server_pubsub_publisher_iop.c

@@ -3,6 +3,9 @@
 
 #include <open62541/plugin/log_stdout.h>
 #include <open62541/plugin/pubsub_udp.h>
+#ifdef UA_ENABLE_PUBSUB_ETH_UADP
+#include <open62541/plugin/pubsub_ethernet.h>
+#endif
 #include <open62541/server.h>
 #include <open62541/server_config_default.h>