Put a comment start symbol at the start of a comment that lacked one.
diff --git a/Modules/Setup.in b/Modules/Setup.in
index ffbf64f..3fe98f1 100644
--- a/Modules/Setup.in
+++ b/Modules/Setup.in
@@ -111,7 +111,7 @@
# STDWIN toplevel directory. The ARCH variable must be set to the
# architecture identifier used to build STDWIN. NB if you combine this
# with the gl module on an SGI IRIX 4 machine, you should replace
-"-lX11" with "-lX11_s".
+# "-lX11" with "-lX11_s".
#STDWIN=/ufs/guido/src/stdwin
#ARCH=???