test/openssl/test_pkcs12: fix test failures with OpenSSL 3.0

OpenSSL's PKCS12_create() by default uses pbewithSHAAnd40BitRC2-CBC for
encryption of the certificates. However, in OpenSSL 3.0, the algorithm
is part of the legacy provider and is not enabled by default.

Specify another algorithm that is still in the default provider for
these test cases.

Author: rhenium