Add SO_REUSEPORT

[mesaglio]

Add some like this to solve port issues on lab

int iniciar_servidor(void)
{
// Quitar esta línea cuando hayamos terminado de implementar la funcion
	assert(!"no implementado!");

	int socket_servidor;
	...
	uint32_t flag = 1;
	setsockopt(socket_servidor, SOL_SOCKET, SO_REUSEPORT, &flag, sizeof(flag));
	...

[RaniAgus]

I would rather add it to https://docs.utnso.com.ar/guias/linux/sockets#bind-y-listen
Related: sisoputnfrba/docs#105

[mesaglio]

To both