message: [Python] Fixed potential allignment issue
diff: @@ -515,7 +515,7 @@ class Builder(object):
  N.enforce_number(rootTable, N.UOffsetTFlags)
  if file_identifier is not None:
  - self.Prep(N.UOffsetTFlags.bytewidth, N.Uint8Flags.bytewidth*4)
  + self.Prep(N.UOffsetTFlags.bytewidth, encode.FILE_IDENTIFIER_LENGTH)
  # Convert bytes object file_identifier to an array of 4 8-bit integers,
  # and use big-endian to enforce size compliance.
  