Can't restart servers due to missing SO_REUSEADDR

[iabdalkader]

It's not possible to re-bind a server socket to the same port because SO_REUSEADDR is not set on server sockets, and AFAIK there's no function to set socket-level options. The second time bind() is called with the same port it fails and the socket is closed, in WiFiServer::begin() here:

https://github.com/arduino/nina-fw/blob/master/arduino/libraries/WiFi/src/WiFiServer.cpp#L57

What makes it worse is the result from begin() is completely ignored:

https://github.com/arduino/nina-fw/blob/master/main/CommandHandler.cpp#L406

Also it seems the port never becomes free again ever without a hard-reset.