Wrap pe-parsing in try/catch.

[clearbluejar]

Found in #65

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Users\User\AppData\Local\Programs\Python\Python311\Scripts\ghidriff.exe\__main__.py", line 7, in <module>
  File "C:\Users\User\AppData\Local\Programs\Python\Python311\Lib\site-packages\ghidriff\__main__.py", line 82, in main
    pdiff = d.diff_bins(diff[0], diff[1])
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\User\AppData\Local\Programs\Python\Python311\Lib\site-packages\ghidriff\ghidra_diff_engine.py", line 1446, in diff_bins
    pdiff['old_pe_url'] = self.get_pe_download_url(old, pdiff['old_meta'][pe_key])
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\User\AppData\Local\Programs\Python\Python311\Lib\site-packages\ghidriff\ghidra_diff_engine.py", line 820, in get_pe_download_url
    pe_info = get_pe_extra_data(path)
              ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\User\AppData\Local\Programs\Python\Python311\Lib\site-packages\ghidriff\utils.py", line 41, in get_pe_extra_data
    machine = unpack('<H', word)[0]
              ^^^^^^^^^^^^^^^^^^
struct.error: unpack requires a buffer of 2 bytes

Originally posted by @justanotheranonymoususer in #65 (comment)