This is a followup to commit 8f53d73493a2949e2db28cd7d689a690b2d9479a,
which did not have the desired effect: the 'resolve-module' call was
bound to succeed since the inferior runs 'guix repl'.
* guix/ssh.scm (store-import-channel)[import]: Add call to
'resolve-module' and write '(module-error) upon error. Write
'(importing) when we're ready.
(send-files)[inferior-remote-eval*]: Remove.
[missing]: Remove call to 'resolve-module'.
Call 'handle-import/export-channel-error' when PORT doesn't
return '(importing).
(handle-import/export-channel-error): New procedure.
(retrieve-files*): Use it.