Ignore IOError when closing connections

[fghzxm]

Closing client streams can throw IOError if the client connection has been reset by the peer, in which case we simply ignore the error and continue the cleanup.

[fonsp]

Nice! Can you rename it to swallow_exception and swap the function arguments? https://docs.julialang.org/en/v1/manual/style-guide/#Write-functions-with-argument-ordering-similar-to-Julia-Base

[fghzxm]

Should be OK now, I hope there aren't any minor problems left

[fonsp]

Awesome, thanks!