Upgrade soy to 2019-09-03

Change-Id: Id897351873a68186fd6db87ef0aaf2615948732e

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 5a2c71e..983074b 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -130,8 +130,8 @@
 
 maven_jar(
     name = "soy",
-    artifact = "com.google.template:soy:2019-08-22",
-    sha1 = "d4bf390caf7aa448108a5b9ec1b51f46820438f3",
+    artifact = "com.google.template:soy:2019-09-03",
+    sha1 = "40781da0302b4b5d53006dc8bd5a432c7288d807",
 )
 
 maven_jar(