[Backport] FIXED: FTP user and password strings urldecoded

[mage2pratik]

Original Pull Request

#16876

Description

FTP connections can't use user or password strings with special characters, like @ or #.
$user = 'my@mail.com';
$pass = '#my@pass';
$host = 'ftphost.com';
$ftp->connect("ftp://{$user}:{$pass}@{$host}");

connect() calls parse_url() and this will break down bad the special chars...

Solution:
// ...
$user = urlencode($user);
$pass = urlencode($pass);
$ftp->connect( ... );

But connect() method calls ftp_login() without decode the $user and $pass vars

Manual testing scenarios

1. $ftp->connect("ftp://my%23mail.com:mypass@myhost.com"); // this works
2. $ftp->connect("ftp://no_special_chars:mypass@myhost.com"); // this works too

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

Hi @ihor-sviziev, thank you for the review.
ENGCOM-2569 has been created to process this Pull Request

[magento-engcom-team]

Hi @mage2pratik. Thank you for your contribution.
We will aim to release these changes as part of 2.1.15.
Please check the release notes for final confirmation.