Bogus call to ERR_get_error

[pepone]

The call to ERR_get_error consumes the error, if we enter the else branch the error would be empty. We should instead use Err_peek_error. We should review other calls to Err_get_error and check for similar issues.

https://github.com/zeroc-ice/ice/blob/711bb2939294bb1dbb940e3a4a6966e89c5ed735/cpp/src/IceSSL/OpenSSLTransceiverI.cpp#L402-L416