[Backport] Changed storage.php

[MartinAarts]

renamed variable on line 572 & 589, from $keepRation to $keepRatio.
As noted in issue #17587

Backport for: #17596

[magento-engcom-team]

Hi @MartinAarts. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me {$VERSION} instance - deploy vanilla Magento instance

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[magento-engcom-team]

Hi @ihor-sviziev, thank you for the review.
ENGCOM-2872 has been created to process this Pull Request

[magento-engcom-team]

@MartinAarts thank you for contributing. Please accept Community Contributors team invitation here to gain extended permissions for this repository.

[magento-engcom-team]

Hi @MartinAarts. Thank you for your contribution.
We will aim to release these changes as part of 2.2.7.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.