Update ukey2 again after securemessage was updated.
diff --git a/third_party/secure_message b/third_party/secure_message
index 69a0298..e7b6988 160000
--- a/third_party/secure_message
+++ b/third_party/secure_message
@@ -1 +1 @@
-Subproject commit 69a02984d4563c6c21132ee882d1d3df1981f5a1
+Subproject commit e7b6988454bc94601616fbbf0db3559f73a1ebdf