[gnome-autoar] GTK-Doc must be enabled to run `make distcheck'

[Ting-Wei Lan <lantw src gnome org>]

commit d4d06de8ba86f4799f2706fe28b4a1347188b5cd
Author: Ting-Wei Lan <lantw44 gmail com>
Date:   Wed Sep 11 21:42:17 2013 +0800

    GTK-Doc must be enabled to run `make distcheck'

 Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 505166f..ec407d7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -9,3 +9,5 @@ SUBDIRS = gnome-autoar data tests docs
 EXTRA_DISTS = \
        autogen.sh \
        $(NULL)
+
+DISTCHECK_CONFIGURE_FLAGS = --enable-gtk-doc