do not have to use the same distributionAlgo as first pool (#19031)

when we expand via pools, there is no reason to stick
with the same distributionAlgo as the rest. Since the
algo only makes sense with-in a pool not across pools.

This allows for newer pools to use newer codepaths to
avoid legacy file lookups when they have a pre-existing
deployment from 2019, they can expand their new pool
to be of a newer distribution format, allowing the
pool to be more performant.

cmd/api-errors.go

@@ -2351,7 +2351,7 @@ func toAPIErrorCode(ctx context.Context, err error) (apiErr APIErrorCode) {
 	case dns.ErrBucketConflict:
 		apiErr = ErrBucketAlreadyExists
 	default:
-		if strings.Contains(err.Error(), "requested declared a Content-Length") {
+		if strings.Contains(err.Error(), "request declared a Content-Length") {
 			apiErr = ErrIncompleteBody
 		} else {
 			apiErr = ErrInternalError