It is still required to set beneficiary to enable devmode

[davidyuk]

the last time reported in #1760 (comment)

currently, if I remove beneficiary then

docker compose exec middleware ./bin/ae_mdw rpc ":aeplugin_dev_mode_app.start_unlink()"

fails with

Command failed: docker compose exec middleware ./bin/ae_mdw rpc ":aeplugin_dev_mode_app.start_unlink()"
** (exit) exited in: :gen_server.call(:aeplugin_dev_mode_emitter, {:auto_emit_microblocks, true})
    ** (EXIT) no process: the process is not alive or there's no process currently associated with the given name, possibly because its application isn't started
    (stdlib 5.2.3.1) gen_server.erl:404: :gen_server.call/2
    nofile:1: (file)
    (stdlib 5.2.3.1) erl_eval.erl:750: :erl_eval.do_apply/7
    (elixir 1.17.3) lib/code.ex:572: Code.validated_eval_string/3