Cosmetic bug
`show vpn ipsec sa` shows unexpected prefix `B` in packets
```
vyos@r14:~$ show vpn ipsec sa
Connection State Uptime Bytes In/Out Packets In/Out Remote address Remote ID Proposal
------------------------- ------- -------- -------------- ---------------- ---------------- ----------- ------------------------
peer_192-0-2-2_tunnel_0 up 21m20s 420B/420B 5B/5B 192.0.2.2 192.0.2.2 AES_GCM_16_256/MODP_2048
```
It seems `filesize.size` if wrong option for packets
https://github.com/vyos/vyos-1x/blob/38d753f830887c35abe4fbcf1bb73b6f26be1fdf/src/op_mode/show_ipsec_sa.py#L75-L78
Could be fixed with replace https://github.com/vyos/vyos-1x/blob/494f1f3473d07947e3e03ce410ac0690eaeb9ed9/src/op_mode/show_ipsec_sa.py#L74-L75
Or suggestion from @zsdc
```
if sa_packets_in and sa_packets_out:
if int(sa_packets_in.decode()) < 1000:
packets_in = sa_packets_in
else:
packets_in = filesize.size(int(sa_packets_in.decode()),
system=filesize.si)
if int(sa_packets_out.decode()) < 1000:
packets_out = sa_packets_out
else:
packets_out = filesize.size(int(
sa_packets_out.decode()),
system=filesize.si)
sa_out_packets = f'{packets_in}/{packets_out}'
```