build: update to latest gnulib

Mainly for -fsanitize=address and -fsanitize=undefined fixes

diff --git a/gnulib b/gnulib
index d0302f003873b8c633d2023ab98aa6c4045b32e8..49078a780041205fbbab56802033595eb44f854d 160000 (submodule)
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit d0302f003873b8c633d2023ab98aa6c4045b32e8
+Subproject commit 49078a780041205fbbab56802033595eb44f854d