MEDIUM: conn_stream: Add a pointer to the app object into the conn-stream

In the same way the conn-stream has a pointer to the stream endpoint , this
patch adds a pointer to the application entity in the conn-stream
structure. For now, it is a stream or a health-check. It is mandatory to
merge the stream-interface with the conn-stream.
diff --git a/src/mux_pt.c b/src/mux_pt.c
index 13e60d8..7ba9da9 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -291,7 +291,7 @@
 	ctx->conn = conn;
 
 	if (!cs) {
-		cs = cs_new(&conn->obj_type);
+		cs = cs_new(&conn->obj_type, NULL, NULL, NULL, NULL);
 		if (!cs) {
 			TRACE_ERROR("CS allocation failure", PT_EV_STRM_NEW|PT_EV_STRM_END|PT_EV_STRM_ERR, conn);
 			goto fail_free_ctx;