xonsh: Fix broken tests
xonsh: Fix broken tests

Pulls in a patch committed a couple of days after the 0.9.13 release
(the one here), to fix the tests.

(cherry picked from commit bf822c4caa96666d5ee1c20870229b9f6484e5cd)

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs