Do not warn about a BrokenPipeError we do consider - Fix #2622

[nathdwek]

For some reason Python always warns about a BrokenPipeError on
stderr even if it is caught.

This should fix #2622 and seems pretty harmless, since stderr is systematically flushed by other error messages.
@Azphreal , could we get some feedback from your end before merging?

[mention-bot]

@nathdwek, thanks for your PR! By analyzing the history of the files in this pull request, we identified @sampsyo, @geigerzaehler and @brunal to be potential reviewers.

[sampsyo]

This looks perfect! If @Azphreal confirms, this is ready to merge.

[xeals]

Change does indeed fix the error.

Interestingly enough, the current version from git (which still used pass rather than closing stderr) didn't have the issue for me, which meant it'd probably been fixed (unintentionally or not) since 1.4.5.

[nathdwek]

Mmmmh, that's weird, I can still reproduce this from the master branch.

[sampsyo]

That's strange! @Azphreal, any chance you unconsciously switched Python versions when trying the master branch? 😃

[xeals]

Python version is still 3.5.2, so I don't think so.

[sampsyo]

Very strange. In any case, this looks like the right fix. I’ll leave it to you to merge if you think it’s ready, @nathdwek! 🐟 🚀

[nathdwek]

@Azphreal could you keep your ear to the ground on this one? I'll merge and remain careful for weird things popping up.