main/openssh: remove sftp-interactive.patch

This patch changes code that is only executed when OpenSSH is compiled without editline support. I assume, in 2014 (when this patch was added) this was still the case. However, nowadays we compile OpenSSH with editline support, hence the prompt is drawn by editline and we no longer need this patch.

Nonetheless, since the problem still persists when OpenSSH is compiled without editline support, hence I also proposed the patch for upstream integration: https://github.com/openssh/openssh-portable/pull/480