build: Create m4 directory

Create m4 directory before running gnome-autogen.sh. With this, build
fails in maemo6 scratcbox environment.

diff --git a/autogen.sh b/autogen.sh
index 9434457..a015002 100755 (executable)
--- a/autogen.sh
+++ b/autogen.sh
@@ -5,6 +5,7 @@ which gnome-autogen.sh || {
     exit 1
 }
 
+mkdir m4
 gnome-autogen.sh --enable-vala --enable-maintainer-mode --enable-debug \
                  --enable-test-plugin --enable-mediathek-plugin \
                  --enable-gst-launch-plugin "$@"