dbus: add bbappend to fix upgrade path

 * check_data_file_clashes: Package dbus-1 wants to install file /lib/systemd/system/multi-user.target.wants/dbus.service
        But that file is already provided by package  * dbus-systemd
 * check_data_file_clashes: Package dbus-1 wants to install file /lib/systemd/system/dbus.socket
        But that file is already provided by package  * dbus-systemd
 * check_data_file_clashes: Package dbus-1 wants to install file /lib/systemd/system/sockets.target.wants/dbus.socket
        But that file is already provided by package  * dbus-systemd

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>