s3: fix configuring IAM for the same user

hi, how can I add bucket permission to a user now?
Previously, if I needed to add permission to an existing credential, I simply repeated the s3.configure command with a different bucket name.
Now I am getting error:
duplicate accessKey[ХХХХ], already configured in user[YYYY]

s3.configure -access_key key -actions Read,Write,List -buckets bucket1 -secret_key secr -user user1
s3.configure -access_key key -actions Read,Write,List -buckets bucket2 -secret_key secr -user user1

weed/filer/s3iam_conf.go

@@ -43,7 +43,7 @@ func CheckDuplicateAccessKey(s3cfg *iam_pb.S3ApiConfiguration) error {
 		for _, cred := range ident.Credentials {
 			if userName, found := accessKeySet[cred.AccessKey]; !found {
 				accessKeySet[cred.AccessKey] = ident.Name
-			} else {
+			} else if userName != ident.Name {
 				return fmt.Errorf("duplicate accessKey[%s], already configured in user[%s]", cred.AccessKey, userName)
 			}
 		}

weed/filer/s3iam_conf_test.go

@@ -97,6 +97,41 @@ func TestCheckDuplicateAccessKey(t *testing.T) {
 			},
 			"",
 		},
+		{
+			&iam_pb.S3ApiConfiguration{
+				Identities: []*iam_pb.Identity{
+					{
+						Name: "some_name",
+						Credentials: []*iam_pb.Credential{
+							{
+								AccessKey: "some_access_key1",
+								SecretKey: "some_secret_key1",
+							},
+						},
+						Actions: []string{
+							ACTION_ADMIN,
+							ACTION_READ,
+							ACTION_WRITE,
+						},
+					},
+					{
+						Name: "some_name",
+						Credentials: []*iam_pb.Credential{
+							{
+								AccessKey: "some_access_key1",
+								SecretKey: "some_secret_key1",
+							},
+						},
+						Actions: []string{
+							ACTION_READ,
+							ACTION_TAGGING,
+							ACTION_LIST,
+						},
+					},
+				},
+			},
+			"",
+		},
 		{
 			&iam_pb.S3ApiConfiguration{
 				Identities: []*iam_pb.Identity{