snowflake-01: Change upper value for local port range

We have increased the range of local TCP and UDP ports to span from 15000 and 64000 inclusive. The kernel has opinions and prints the following at boot:

kernel: ip_local_port_range: prefer different parity for start/end values.

https://docs.kernel.org/5.10/networking/ip-sysctl.html explains that

If possible, it is better these numbers have different parity (one even and one odd value).

I suggest we change the upper value to 63999 for upcoming boots by editing /etc/sysctl.d/ip_local_port_range.conf.

/cc @dcf