In zettair, back to automake 1.15?

diff --git a/zettair b/zettair
index 911629b..1d02c0e 160000 (submodule)
--- a/zettair
+++ b/zettair
@@ -1 +1 @@
-Subproject commit 911629b0d0e946b4e9409bcfefe4e1db7d7aa9bd
+Subproject commit 1d02c0eb3139b9ededa3a6e5fbf0d820eaa5f14a