auto-version.in: Fix the description in the header comment.

diff --git a/build/auto-version b/build/auto-version
index 7cdeee8..ee7de76 100755 (executable)
--- a/build/auto-version
+++ b/build/auto-version
@@ -1,7 +1,7 @@
 #! /bin/sh
 ### -*-sh-*-
 ###
-### Make autoconf-like substitutions in files
+### Guess at the project's version number
 ###
 ### (c) 2008 Mark Wooding
 ###