REGTESTS: ssl: Reenable ssl_errors test for OpenSSL only

The test is strongly dependent on the way the errors are output by the
SSL library so it is not possible to perform the same checks when using
OpenSSL or LibreSSL. It is then reenabled for OpenSSL (whatever the
version) but still disabled for LibreSSL.
This limitation is added thanks to the new ssllib_name_startswith
precondition check.
1 file changed