pypi import certs issues

[c4droid <c4droid@foxmail.com>]

Hi, Guix!

on commit dc5430c9dc20ee53441995d9a89a90b0a86aeed3 pypi import has
issues:

Backtrace:
In ice-9/eval.scm:
    619:8 19 (_ #(#(#<directory (guile-user) 7fb1cb718c80>)))
In guix/ui.scm:
   2300:7 18 (run-guix . _)
  2263:10 17 (run-guix-command _ . _)
In guix/scripts/import.scm:
    89:11 16 (guix-import . _)
In ice-9/boot-9.scm:
  1752:10 15 (with-exception-handler _ _ #:unwind? _ # _)
In guix/scripts/import/pypi.scm:
    97:21 14 (_)
In guix/import/utils.scm:
   638:27 13 (recursive-import "pwntools" #:repo->guix-package _ # . #)
   630:33 12 (lookup-node "pwntools" #f)
In guix/memoization.scm:
     98:0 11 (mproc "pwntools" #:version #f #:repo->guix-package #<…> …)
In unknown file:
          10 (_ #<procedure 7fb1c7d05a20 at guix/memoization.scm:17…> …)
In guix/import/pypi.scm:
   495:21  9 (_ "pwntools" #:version _)
   126:10  8 (pypi-fetch _)
In ice-9/exceptions.scm:
   406:15  7 (json-fetch _ #:http-fetch _ #:headers _)
In ice-9/boot-9.scm:
  1752:10  6 (with-exception-handler _ _ #:unwind? _ # _)
In guix/import/json.scm:
    53:19  5 (_)
In guix/http-client.scm:
   107:28  4 (http-fetch _ #:port _ #:text? _ #:buffered? _ # _ # _ # …)
In guix/build/download.scm:
    468:4  3 (open-connection-for-uri _ #:timeout _ # _)
    360:6  2 (tls-wrap #<closed: file 7fb1c7a3ce00> _ # _)
In ice-9/boot-9.scm:
  1685:16  1 (raise-exception _ #:continuable? _)
  1683:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1683:16: In procedure raise-exception:
X.509 certificate of 'pypi.org' could not be verified:
  revocation-data-superseded
  invalid

I found a old discuss in
https://lists.gnu.org/archive/html/guix-devel/2018-03/msg00247.html,
but set SSL_CERTS_DIR to /etc/ssl/certs don't working.

The environment variable for SSL:
GIT_SSL_CAINFO=/etc/ssl/certs/ca-certificates.crt
SSL_CERT_DIR=/run/current-system/profile/etc/ssl/certs
SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt