MINOR: stream-int: export stream_int_update_*

Not only these functions were not static, but we'll also want to export
them.
diff --git a/include/proto/stream_interface.h b/include/proto/stream_interface.h
index 84c3090..d1d75ba 100644
--- a/include/proto/stream_interface.h
+++ b/include/proto/stream_interface.h
@@ -49,6 +49,8 @@
 struct appctx *stream_int_register_handler(struct stream_interface *si, struct applet *app);
 void si_applet_done(struct stream_interface *si);
 void stream_int_update(struct stream_interface *si);
+void stream_int_update_conn(struct stream_interface *si);
+void stream_int_update_applet(struct stream_interface *si);
 
 /* returns the channel which receives data from this stream interface (input channel) */
 static inline struct channel *si_ic(struct stream_interface *si)