Fix ServletUriComponentsBuilder examples in ref docs

[wkwkhautbois]

Fix ServletUriComponentsBuilder examples in reference docs.

Fixed two problems.

• Type mismatch
• Comments are inaccurate

before

// Re-uses host, port and context path...

ServletUriComponentsBuilder ucb = ServletUriComponentsBuilder.fromContextPath(request)
        .path("/accounts").build()

after

// Re-uses host, port, scheme and context path...

URI uri = ServletUriComponentsBuilder.fromContextPath(request)
        .path("/accounts")
        .build()
        .toUri();

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[sbrannen]

Good catch!

This has been merged into 5.3.x and main.

Thanks for making your first contribution to the Spring Framework. 👍