With CONFIG_ESP_MAIN_TASK_AFFINITY_NO_AFFINITY=y the main task could
switch core between registering the idle hook and the while loop.
This would cause a deadlock were the current task was waiting for the
idle hook to run on the same core it's busy waiting.
Merge https://github.com/espressif/esp-idf/pull/16149
Make it possible to set the DNS servers to provide to the peer. This is
useful when acting as a PPP server.
If any DNS server is set, don't request a DNS server from the peer.