Go test fails for windows environment

System information

Geth version: geth 1.8.13
OS & Version: Windows
Commit hash : v1.8.13

Actual behaviour

Testing go test on windows environment fails on windows environment including Appveyor CI build.

I think it is related to #17041 PR with swarm POC3 release.

Build result: https://ci.appveyor.com/project/ethereum/go-ethereum/build/master.7006/job/tocjijjprtmv4tac

@fjl @karalabe @zsfelfoldi @gbalint

[nonsense]

This has been fixed as part of b3711af by @janos