Update content/en/user-guide/aws/rds/index.md

Co-authored-by: Nikos <nikos.michas@localstack.cloud>

Author: HarshCasper

content/en/user-guide/aws/rds/index.md

@@ -180,7 +180,7 @@ For instance, the `storage-encrypted` flag is returned as configured, but active
 
 When you establish an RDS DB cluster or instance using the `postgres`/`aurora-postgresql` DB engine along with a specified `EngineVersion`, LocalStack will dynamically install and configure the corresponding PostgreSQL version as required.
 Presently, you have the option to choose major versions ranging from 11 to 17.
-If you select a major version beyond this range, the system will automatically default to version 17.
+If you select a major version beyond this range, the system will automatically default to version 15.
 
 It's important to note that the selection of minor versions is not available.
 The latest major version will be installed within the Docker environment.