Specify the list of constants to be imported

[guedou]

This fixes #4402

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 81.48%. Comparing base (b0506a1) to head (d5836f4).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #4403 +/- ## ========================================== - Coverage 82.19% 81.48% -0.72% ========================================== Files 352 352 Lines 83994 83995 +1 ========================================== - Hits 69038 68441 -597 - Misses 14956 15554 +598 ``` | [Files](https://app.codecov.io/gh/secdev/scapy/pull/4403?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=secdev) | Coverage Δ | | |---|---|---| | [scapy/consts.py](https://app.codecov.io/gh/secdev/scapy/pull/4403?src=pr&el=tree&filepath=scapy%2Fconsts.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=secdev#diff-c2NhcHkvY29uc3RzLnB5) | `100.00% <100.00%> (ø)` | | ... and [18 files with indirect coverage changes](https://app.codecov.io/gh/secdev/scapy/pull/4403/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=secdev)