[gtk-doc] configure: use more compatible option for highlight

[Stefan Kost <stefkost src gnome org>]

commit 24b3544330758e07ee159a0e3217e05fe82382bf
Author: Stefan Kost <ensonic users sf net>
Date:   Wed Apr 13 15:05:01 2011 +0300

    configure: use more compatible option for highlight
    
    Hightlight change the version between 2.16 and 3.4. Both versions have
    --out-format, so lets use that one.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 30fe622..72f2b0f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -115,7 +115,7 @@ if test "$with_highlight" = "auto"; then
 	else
 		AC_PATH_PROG([HIGHLIGHT], [highlight])
 		if test -n "$HIGHLIGHT"; then
-			HIGHLIGHT_OPTIONS="-X -f --class-name=gtkdoc "
+			HIGHLIGHT_OPTIONS="--out-format=xhtml -f --class-name=gtkdoc "
 		else
 			AC_PATH_PROG([HIGHLIGHT], [vim])
 			if test -n "$HIGHLIGHT"; then