updated open api specification link prior to release

Author: jamesdbloom

mockserver-core/src/main/java/org/mockserver/validator/jsonschema/JsonSchemaValidator.java

@@ -30,7 +30,7 @@
  */
 public class JsonSchemaValidator extends ObjectWithReflectiveEqualsHashCodeToString implements Validator<String> {
 
-    public static final String OPEN_API_SPECIFICATION_URL = "See: https://app.swaggerhub.com/apis/jamesdbloom/mock-server-openapi/5.8.x for OpenAPI Specification";
+    public static final String OPEN_API_SPECIFICATION_URL = "See: https://app.swaggerhub.com/apis/jamesdbloom/mock-server-openapi/5.9.x for OpenAPI Specification";
     private static final Map<String, String> schemaCache = new ConcurrentHashMap<>();
     private final MockServerLogger mockServerLogger;
     private final String schema;