Fixed IPv6 issue

[monochromec]

Cf. #75

[romanvm]

With all due respect, socket host binding has nothing to do with the referenced issue.

[monochromec]

Strangely enough, it does fix the issue though. 😊

[romanvm]

Probably, I'm not that familiar with Python's socket module internals, but I don't want to limit the default address range for the web console. set_trace() does accept host as a parameter so you can specify it explicitly as a workaround.