Fixed the problem that packet id: "FAIL" was returned when UTF8 characters appeared in the "path" parameter of the "push" method.

[flyfishxu]

In the period version, "java.io.IOException: Unexpected sync packet id: FAIL" was thrown when UTF8 characters appeared in the path parameter of the push method.

Because characters other than ASCII do not occupy only one byte in UTF8 encoding, so using the "remote.length" method to calculate the byte length will result in an incorrect length result, resulting in a "FAIL".