Update libtermcolor

diff --git a/util b/util
index 8becfa1fe92044e097d089cfb67c1967c87f76fb..91c2b6eb175248ef7f3e6dcd8a0b62bb62ada660 160000 (submodule)
--- a/util
+++ b/util
@@ -1 +1 @@
-Subproject commit 8becfa1fe92044e097d089cfb67c1967c87f76fb
+Subproject commit 91c2b6eb175248ef7f3e6dcd8a0b62bb62ada660