function create503ErrorResponse(sMessageCode = "HTTP 503", bCrashBatch = true) {
		return createErrorResponse({
			crashBatch: bCrashBatch,
			message: "Service Unavailable",
			statusCode: 503,
			headers: {"Retry-After": 5},
			messageCode: sMessageCode
		});
	}
Creates an error response object for a 503 "Retry-After" HTTP error.

@param {string} [sMessageCode="HTTP 503"] The message code
@param {boolean} [bCrashBatch=true] Whether the complete batch request shall fail
@returns {object} The 503 error response