Use SHA265 for generating self signed certificates

[stormbyte]

• [x] There is an issue ticket which accompanies my PR: https://github.com/weprovide/valet-plus/issues/520
• [x] I have followed the guidelines for contributing.
• [x] I have checked that there aren't other open pull requests for the same issue ticket.
• [x] I have formatted my code with the PSR-2 coding style before submitting my PR.

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I have read the contribution guidelines and am targeting the branch 2.x:
Because this is a Bug Fix which is Backwards Compatible. Should be backwards compatible as it is an additional option to openssl. Rest of the code should not be affected Changed to 2.x branch because build does not work for PHP5.6

Changelog entry:
Add to the openssl command that it should use the sha265 encryption

[stormbyte]

Test fail because test php 5.6 environment with php 7.x code ??

[Neodork]

/AzurePipelines run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[Neodork]

/AzurePipelines run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[Neodork]

/AzurePipelines run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[stormbyte]

/AzurePipelines run

[azure-pipelines[bot]]

Commenter does not have sufficient privileges for PR 522 in repo weprovide/valet-plus

[SanderAtom]

This works for me 👍

[mischabraam]

Also merged to release/2.4 branch.