fix: reject start-after in ListObjects V1

listobjects v1 now returns InvalidArgument when the start-after query parameter is present, matching s3, which only accepts it with list-type=2. previously the parameter was silently ignored.

Fixes #2004

s3err/invalid-argument.go

@@ -26,6 +26,7 @@ type InvalidArgErrorCode int
 const (
 	InvalidArgMaxBuckets InvalidArgErrorCode = iota
 	InvalidArgNegativeMaxKeys
+	InvalidArgStartAfter
 	InvalidArgObjectAttributes
 	InvalidArgPartNumber
 	InvalidArgCompleteMpPartNumber
@@ -90,6 +91,10 @@ var invalidArgErrResponses = map[InvalidArgErrorCode]InvalidArgumentError{
 		Description:  "max-keys cannot be negative",
 		ArgumentName: "maxKeys",
 	},
+	InvalidArgStartAfter: {
+		Description:  "startAfter only supported in REST.GET.BUCKET with list-type=2",
+		ArgumentName: "start-after",
+	},
 	InvalidArgObjectAttributes: {
 		Description:  "Invalid attribute name specified.",
 		ArgumentName: "x-amz-object-attributes",