build: Create m4 directory
build: Create m4 directory

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

Pelagicore/Media-Manager-Rygel-patched,jku/rygel,luisbg/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,jku/rygel,Tarnyko/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,Tarnyko/rygel