FLAGSAPI-1581 removed the 504 retry guidance (#657)

Author: stuartmcneill1-nhs

specification/summary-care-record.yaml

@@ -353,8 +353,7 @@ paths:
         "504":
           description: |
             The request timed out during processing. This does not imply the request has failed or been rejected.
-            Re-send the request using the same `X-Request-ID` value. Wait 5 seconds before the first retried request.
-            Where multiple retries are necessary, adopt an exponential back-off approach.
+            Re-send the request using the same `X-Request-ID` value.
           content:
             application/fhir+json:
               schema: