Issue #1770: z3 python error is still misleading when import libz3.so

[tamas-visy]

Hey,

I'm opening a new issue related to #1770:

Looks like this final section of the fix

if _lib is None:
  print(_failures)
  …

is missing from the merged pull request 6bacf09 and so the error message is still misleading, hiding the real cause in case of failure.

Originally posted by @tamas-visy in #1770 (comment)