MEDIUM: conn-stream: Be prepared to use an appctx as conn-stream endpoint

To be able to use an appctx as conn-stream endpoint, the connection is no
longer stored as is in the conn-stream. The obj-type is used instead.
diff --git a/src/h3.c b/src/h3.c
index 31b9c00..bda2a46 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -176,7 +176,7 @@
 	if (fin)
 		htx->flags |= HTX_FL_EOM;
 
-	cs = cs_new(qcs->qcc->conn, qcs->qcc->conn->target);
+	cs = cs_new(qcs->qcc->conn->obj_type);
 	if (!cs)
 		return 1;