Bug in LFS import when import_url user or password have invalid characters

Imagine the import_url of a project is something like http://t+u:a#b@example.com. When we try to parse it using Addressable::URI.parse or URI.parse it will raise an error.

In order to avoid this, in https://gitlab.com/gitlab-org/gitlab-ce/commit/50ff36265016728ab9372bff6b16b49e2d2364d6, we used Gitlab::UrlSanitizer in between of this process. So now, when you query the project import_url it will return the encoded version of the url (http://t%2Bu:a%23b@example.com).

Nevertheless, in the LFS import workflow, these encoding changes weren't reflected. That means, when LfsDownloadLinkListService asks for the oids' links in get_download_links, it will be using invalid credentials, http://t%2Bu:a%23b@example.com/info/lfs/objects/batch, and it will also build invalid links.

To fix this we need to unencode the user and password before requesting any data.