Update rabbitmq_auth_mechanism_ssl/README.md so openssl command is easier to change after pasting. (backport #12822)

[mergify]

Proposed Changes

This changes the line openssl x509 -in path/to/cert.pem -nameopt RFC2253 -subject -noout to put the -in parameter at the end of the line, so that it's easier to ^W the path and replace it with another path.

Tested that this works with OpenSSL 3.1.6 4 Jun 2024 (Library: OpenSSL 3.1.6 4 Jun 2024) and OpenSSL 3.3.0 9 Apr 2024 (Library: OpenSSL 3.3.0 9 Apr 2024) on an Ubuntu 22.04.4 container and MacOS 14.7.1

Types of Changes

This is a single line documentation change to deps/rabbitmq_auth_mechanism_ssl/README.md

Checklist

• I have read the CONTRIBUTING.md document
• I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• I have added tests that prove my fix is effective or that my feature works
• All tests pass locally with my changes
• If relevant, I have added necessary documentation to https://github.com/rabbitmq/rabbitmq-website
• If relevant, I have added this change to the first version(s) in release-notes that I expect to introduce it

Further Comments

This is a trivial commit that I hope will be accepted for convenience. Thank you!

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This is an automatic backport of pull request #12822 done by Mergify.