change simple slideAdminHash with sha256

[andyoknen]

Standards checklist:

• The PR title is descriptive.
• The PR doesn't replicate another PR which is already open.
• The PR has self-explained commits history.

• The code is mine or it's from somewhere with an Apache-2.0 compatible license.
• The code is efficient, to the best of my ability, and does not waste computer resources.
• The code is stable and I have tested it myself, to the best of my abilities.
• If the code introduces new classes, methods, I provide a valid use case for all of them.

Changes:

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Other comments:

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[shpingalet007]

@andyoknen is brangr your git profile? Please, consider using the andyoknen email to link your contribution to your profile. It is better not only for the team and for your GitHub profile stats. Commits made from not associated profile are not affect your stats.