Recursive _errno_from_exception

[gustafsson]

Similar to #202 but the socket.error may also have empty args so check the length again, or revert to the errno field.

When I was using a proxy that dropped the connection I got this error message

socks.GeneralProxyError: Connection closed unexpectedly

During handling of the above exception, another exception occurred:
...
  File "~/Applications/google-cloud-sdk/platform/gsutil/third_party/httplib2/python3/httplib2/__init__.py", line 195, in _errno_from_exception
    return e_int.args[0].errno if isinstance(e_int.args[0], socket.error) else e_int.errno
IndexError: tuple index out of range

httplib2_IndexError_tuple_index_out_of_range.txt

[codecov]

Codecov Report

Merging #228 (1141e7e) into master (a309035) will decrease coverage by 0%.
The diff coverage is 75%.

Additional details and impacted files

Impacted Files	Coverage Δ
python3/httplib2/__init__.py	83% <75%> (-1%)	⬇️
python2/httplib2/__init__.py	83% <0%> (+<1%)	⬆️

[temoto]

thank you, recursive version is cleaner