Fix to RemoteBlockInStream.java:read()

Reading from a remote file using RemoteBlockInStream.java:read() causes EOFException in cases where the read character lies in the range 128-255. This is because the result of the underlying read() call returns a byte, which is upgraded to an int without masking with 0xFF, causing values in the range 128-255 being mistaken as negative (EOF) characters.

This fixes the issue by masking the integer with 0xFF before returning.