ReScene crashes when encrypted block headers are used

[Gfy]

Proposed solution: fail and skip rar set, but don't crash

C:\>pysrr test.rar
Invalid RAR block length (58712) at offset 0x19
Parsing RAR file failed. Trying again a couple of times.
Traceback (most recent call last):
  File "\rescene\rar.py", line 1627, in read_all
    return self._found_blocks
AttributeError: 'RarReader' object has no attribute '_found_blocks'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "\rescene\main.py", line 644, in _rarreader_usenet
    return rr.read_all()
  File "\rescene\rar.py", line 1631, in read_all
    for block in self:
  File "\rescene\rar.py", line 1667, in __next__
    block = self._read()
  File "\rescene\rar.py", line 1539, in _read
    ") at offset {0:#x}".format(self._rarstream.tell() - 2))
OSError: Invalid RAR block length (58712) at offset 0x19

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "\rescene\srr.py", line 604, in main
    parser.exit(create_srr(options, infolder, infiles, working_dir))
  File "\rescene\srr.py", line 369, in create_srr
    tmp_srr_name=tmp_srr_name)
  File "\rescene\main.py", line 516, in create_srr
    rarfiles.extend(_handle_rar(infile))
  File "\rescene\main.py", line 924, in _handle_rar
    for block in _rarreader_usenet(rfile, read_retries):
  File "\rescene\main.py", line 660, in _rarreader_usenet
    rarfile.init_data(server_nb=stop)
AttributeError: 'str' object has no attribute 'init_data'
Unexpected Error: 'str' object has no attribute 'init_data'