bug#20809: 25.0.50; package-list-packages never finishes async update if cert bad

[Artur Malabarba]

> If I try it with debug-on-entry, I get a stack trace that begins:
>
>
> Debugger entered--Lisp error: (error "Could not create connection to 
> marmalade-repo.org:443")
>  signal(error ("Could not create connection to marmalade-repo.org:443"))
>  error("Could not create connection to %s:%d" "marmalade-repo.org" 443)
>  url-http([cl-struct-url "https" nil nil "marmalade-repo.org" nil 
> "/packages/archive-contents”…
>

Could we get a little more of that backtrace? :-) It might make it easier.