[seed] Somewhere in the build system reorg, checking for the existence of readline.h was broken. Now fixed.

[Tim Horton <hortont src gnome org>]

commit e8dc85aedf5d4d2eb39c93ff05340c6fc0ff1bcb
Author: Tim Horton <hortont svn gnome org>
Date:   Thu May 7 03:52:52 2009 -0400

    Somewhere in the build system reorg, checking for the existence of readline.h was broken. Now fixed.
---
 configure.ac |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7507093..fa8ab85 100644
--- a/configure.ac
+++ b/configure.ac
@@ -111,8 +111,8 @@ AC_ARG_ENABLE(readline-module,
 			  AC_HELP_STRING([--enable-readline-module],
 							 [enable the readline Seed module. [default=yes]]),
 			  [want_readline_module=$enableval],[want_readline_module="yes"])
-if test x"$want_readline_module" != x"yes" ; then
-	AC_CHECK_HEADER([readline/readline.h])
+if test x"$want_readline_module" == x"yes" ; then
+	AC_CHECK_HEADER([readline/readline.h],,AC_MSG_ERROR([the readline library is not installed.]))
 fi
 
 AM_CONDITIONAL(BUILD_READLINE_MODULE, test "x$want_readline_module" = "xyes")