Typo in v1.6.3 release note

[KENNYSOFT]

https://github.com/springdoc/springdoc-openapi/releases/tag/v1.6.3

Fixed

• OAuth2 implicit flow "client_id" field is empty #405 - Enhance springdoc-openapi as BOM for Gradle

should be:

• Using springdoc-openapi as BOM uses Gradle project verson rather than BOM version #1405

[KENNYSOFT]

@bnasslahsen Actually the linked release is not fixed. 😄