FanOutOneBlockAsyncDFSOutput using shaded protobuf in hdfs 3.3+

The parent added some fancy dancing to make it so on hadoop-3.3.0+ we'd use hadoops shaded protobuf rather than the non-relocated protobuf. When hdfs 3.3, the 'trick' is not working so we continue to use the unshaded protobuf. Fix is trivial.

Found this testing the 3.3.1RC3. Hard to see because whether we use shaded or unshaded is at DEBUG level. If you set DEBUG level and run TestFanOutOneBlockAsyncDFSOutput with hdfs 3.3.1 RC candidate in place you'll see it uses the unshaded protobuf.