npm/ftp fails to clone properly

Created by: varungandhi-src

Reported by Tomás Senart in Slack

[gitserver] WARN error cloning repo, repo: npm/ftp, err: failed to clone npm/ftp: get clone command: failed to fetch repo for [file://npm/ftp](file:///ftp): error pushing dependency "[email protected]": command [git commit --no-verify -m [email protected] --date Thu Apr 8 14:24:52 2021 +0200] failed with output On branch master
[gitserver] Initial commit
[gitserver] nothing to commit (create/copy files and use "git add" to track): exit status 1
[enterprise-repo-updater] ERROR runUpdateLoop: error updating repo, uri: npm/ftp, err: failed to clone npm/ftp: get clone command: failed to fetch repo for [file://npm/ftp](file:///ftp): error pushing dependency "[email protected]": command [git commit --no-verify -m [email protected] --date Thu Apr 8 14:24:52 2021 +0200] failed with output On branch master

One unusual thing I noticed is that the npm/ftp tarball unpacks everything into a folder named mscdex-node-ftp-0bdc638/ instead of the more common package/ directory name. The current code tries to figure out the common directory by doing an extra pass over the tarball, so in theory it shouldn't matter. However, I figured I should point this out since it was not the common case.