Allow Web Services translator to retrieve metadata without source connection

The "ws" translator, is set to "isSourceRequiredForMetadata" to true. However, there are two issues

1) There is no way to turn this flag to false
2) If the "ws" translator is secured through "security-domain", then authentication failure message by passes the "isSourceRequiredForMetadata" flag and returns as error, thus leaving the VDB in "metadata load failed" state.