[auto] Update onnx to 39e4668 - fix optimizer does not set ir_version bug (onnx/onnx#1098)
https://github.com/onnx/onnx/commit/39e46687eafd34c78dd59a1218171371aa3679f1
diff --git a/third_party/onnx b/third_party/onnx
index 2508156..39e4668 160000
--- a/third_party/onnx
+++ b/third_party/onnx
@@ -1 +1 @@
-Subproject commit 2508156135c67f2097aaac42153f641e55fd6c68
+Subproject commit 39e46687eafd34c78dd59a1218171371aa3679f1