Http/SslStress builds failing on main

[antonfirsov]

The build failures started on the 1st of September: https://dev.azure.com/dnceng-public/public/_build/results?buildId=393119&view=logs&j=22fea640-1099-5f32-ec5d-316ad83f359a&t=ebe1360c-fe50-5ebc-628a-48ef9bf66506

Tagging subscribers to this area: @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

Issue Details

---

The build failures started on the 1st of September: https://dev.azure.com/dnceng-public/public/_build/results?buildId=393119&view=logs&j=22fea640-1099-5f32-ec5d-316ad83f359a&t=ebe1360c-fe50-5ebc-628a-48ef9bf66506

Author:	antonfirsov
Assignees:	antonfirsov
Labels:	area-System.Net
Milestone:	9.0.0