Adds the new response "EGeneral:Too many requests" from Kraken to the…

… base service. See knowm#4369 (comment)

xchange-kraken/src/main/java/org/knowm/xchange/kraken/service/KrakenBaseService.java

@@ -87,6 +87,7 @@ public <R> R checkResult(KrakenResult<R> krakenResult) {
           throw new FrequencyLimitExceededException(error);
         case "EOrder:Insufficient funds":
           throw new FundsExceededException(error);
+        case "EGeneral:Too many requests":
         case "EAPI:Rate limit exceeded":
         case "EOrder:Rate limit exceeded":
           throw new RateLimitExceededException(error);