[frogr] Use --force with gnome-doc-prepare

[Mario Sanchez Prada <msanchez src gnome org>]

commit 29130ea9df5ab65b63411f0eeade6e1d6e4881cc
Author: Mario Sanchez Prada <msanchez igalia com>
Date:   Tue May 31 00:42:54 2011 +0200

    Use --force with gnome-doc-prepare

 autogen.sh |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/autogen.sh b/autogen.sh
index 390c697..bea88c2 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -4,7 +4,7 @@ set -e
 aclocal
 autoconf --force
 autoheader --force
-gnome-doc-prepare
+gnome-doc-prepare --force
 automake --add-missing --copy --force-missing --foreign
 glib-gettextize --force --copy
 intltoolize --copy --force --automake