[Bug] tcpreplay-edit recomputes IPv4 checksums unnecessarily

[green-nsk]

Describe the bug

I think this line causes tcpreplay-edit to recompute all checksums for all IP packets unnecessarily. I noticed this because of a problem with recomputing UDP checksums, but in general I think it is 1) not allowing users to replay pcaps with errors 2) waste of time.

To Reproduce

Replay any pcap with errors in IP/UDP/TCP header checksums.

Expected behavior

I expect checksums to stay intact unless explicitly requested

Screenshots

N/A

System (please complete the following information):
All

Additional context

I tried fixing it, but seemingly unrelated tests keep breaking, so I figured I'm in over my head.

[fklassen]

Fixed in PR #846