Update configure-ssl-certificate.md

[patrickmoore-nc]

• Stated 3DES requirement for PFX encryption is no longer accurate. Works fine with AES-256, openssl default algorithm.
• Elliptic curve SSL certificates work only when imported as PFX files, not when imported from Key Vault. See Azure Support Case ref 2505010050001340 where Microsoft confirmed this issue, which for some reason is not documented.
• Since elliptic curve is supported in some fashion, then clearly a key length of 2048bits is no longer a requirement also.

I propose this PR so that it might save someone the colossal waste of time which I experienced.

[prmerger-automator]

@patrickmoore-nc : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

[learn-build-service-prod]

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[v-regandowner]

@msangapu-msft

Can you review the proposed changes?

Due to the upcoming BUILD conference, all merging and publishing is on hold until the morning of May 19th.

Important: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team