Updates the Math submodule to 40803f8.

stan-buildbot · stan-buildbot · commit 55f6e5794c1a · 2021-03-31T00:42:37.000Z
diff --git a/lib/stan_math b/lib/stan_math
@@ -1 +1 @@
-Subproject commit f390d823261266c2a0999eeaedcd5ac216f857b3
+Subproject commit 40803f80dd9e3cdbcfc014b91a9a316d9618fd23
