Fix Swagger errors

[chesseed]

Fixes #

Requirements

All new code should be covered with tests, documentation should be updated. CI should pass.

Description of the Change

This fixes three small errors in the generated swagger file

1. Path parameters are never optional
2. Remove duplicate return annotation
3. Remove duplicated path parameter

Checklist

• unit-test added (if change is algorithm)
• functional test added/updated (if change is functional)
• man page updated (if applicable)
• bash completion updated (if applicable)
• documentation updated
• author name in AUTHORS

[neolynx]

thanks !