Update CHANGELOG.md

Fix pr number in changelog

Author: jonhealy1

CHANGELOG.md

@@ -10,7 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 
 - GET `/collections` collection search structured filter extension with support for both cql2-json and cql2-text formats. [#475](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/475)
-- GET `/collections` collection search query extension. [#476](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/476)
+- GET `/collections` collection search query extension. [#477](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/477)
 - GET `/collections` collections search datetime filtering support. [#476](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/476)
 
 ### Changed