Initial sensible /etc/maxscale.cnf is needed.

Currently, when maxscale is installed, the configuration file is but a template that must be modified before maxscale can be used. That makes the threshold for trying it out higher than what it needs to be.

At installation time if there is not already an existing maxscale.cnf file, a default one should be installed that merely routes all input to a mariadb assumed to exist on the same machine.

That way, it would immediately be possible to use MaxScale without first figuring out how to configure it.