Update SPEC.md

Co-authored-by: pdoerner <[email protected]>

Author: bergundy

SPEC.md

@@ -327,7 +327,7 @@ following predefined error codes.
 | `UPSTREAM_TIMEOUT`   | 520         | Used by gateways to report that a request to an upstream handler has timed out. Subsequent requests by the client are permissible.                                                                |
 
 Client implementations should try to rehydrate a `HandlerError` from the serialized `Failure` object in the response
-body whenever a request fails with one of the status codes listed below. If the handler error type in the `Failure`
+body whenever a request fails with one of the status codes listed above. If the handler error type in the `Failure`
 object details doesn't match the response status code, the `Failure` object takes precendence.
 
 If the serialized `Failure` does not represent a `HandlerError`, clients should construct a wrapper `HandlerError`,