[BUG][Spring] x-spring-paginated fails if no params is defined in the operation

[ilopezv]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
  • swagger.txt (openapi 2.0.0) in oas3 we hava the same problem
• Have you validated the input using an OpenAPI validator (example)?
  • yes
• Have you tested with the latest master to confirm the issue still exists?
  • All 6.x versions up to 6.5.0 included
• Have you searched for related issues/PRs?
  • yes
• What's the actual output vs expected output?
  • In class PrestacionesApiDelegate interface methods should be : obtenerDatosEncuestaDecesos(final Pageable pageable); not obtenerDatosEncuestaDecesos(, final Pageable pageable);
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When using generator spring/spring-cloud and delegatePattern is active:

                <generatorName>spring</generatorName>
                <library>spring-cloud</library>
                <configOptions>
                  <delegatePattern>true</delegatePattern>
                </configOptions>

And try to compile an oas2/oas3 spec with x-spring-paginated: true and no params, generator fails due to the template is introducing a "," prior to Pageable object
obtenerDatosEncuestaDecesos(, final Pageable pageable);

The problem seems to came from this point at apiDelegate.mustache where the "," is introduced always

openapi-generator version

All 6.x versions up to 6.5.0 included

OpenAPI declaration file content or url

swagger.txt

Generation Details

                <generatorName>spring</generatorName>
                <library>spring-cloud</library>
                <configOptions>
                  <delegatePattern>true</delegatePattern>
                </configOptions>

Steps to reproduce

Related issues/PRs

N/A

Suggest a fix

check if no params is defined, and remove "," in this cases.
Problem came from this line in apiDelegate.mustache where the "," is introduced always