Issue #26173: Separate bad cert file tests and client rejection test

Test test_wrong_cert() runs a server that rejects the client's certificate,
so ECONNRESET is reasonable in addition to SSLError. On the other hand, the
other three tests don't even need to run a server because they are just
testing the parsing of invalid certificate files.

Also fix a ResourceWarning by closing the wrapped socket.
1 file changed