session client BUGFIX session wthout transport freeing

Fixes cesnet/netopeer2#1136
diff --git a/src/session_client_tls.c b/src/session_client_tls.c
index 94e8ac5..687d18f 100644
--- a/src/session_client_tls.c
+++ b/src/session_client_tls.c
@@ -759,6 +759,7 @@
     return session;
 
 fail:
+    session->ti_type = NC_TI_NONE;
     session->ti.tls = NULL;
     nc_session_free(session, NULL);
     return NULL;