Also distribute devel/build_chroot

While not strictly necessary for using Ganeti, the distribution
tar ball is still supposed to be a complete for Ganeti development.
Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>

Makefile.am

@@ -1158,6 +1158,7 @@ EXTRA_DIST = \
 	daemons/daemon-util.in \
 	daemons/ganeti-cleaner.in \
 	$(pkglib_python_scripts) \
+	devel/build_chroot \
 	devel/upload \
 	devel/webserver \
 	tools/kvm-ifup.in \