Misleading error message from Rescale(c) when level of c is lowest in FIXEDMANUAL

[Maokami]

HI!
In the following code snippet, rescaling ciphertext twice where multiplicativedepth is one. I guess the second rescale operation is applied to the ciphertext which already has lowest level.

#include "openfhe.h"

using namespace lbcrypto;

int main() {
    CCParams<CryptoContextCKKSRNS> parameters;
    parameters.SetMultiplicativeDepth(1);
    parameters.SetScalingTechnique(FIXEDMANUAL);

    CryptoContext<DCRTPoly> cc = GenCryptoContext(parameters);

    cc->Enable(PKE);
    cc->Enable(LEVELEDSHE);

    auto keys = cc->KeyGen();

    cc->EvalMultKeyGen(keys.secretKey);

    std::vector<double> x1 = {1, 0.5, 0.75, 1.0, 2.0, 3.0, 4.0, 5.0};

    Plaintext ptxt1 = cc->MakeCKKSPackedPlaintext(x1);

    auto c1 = cc->Encrypt(keys.publicKey, ptxt1);
    
    cc -> RescaleInPlace(c1);
    cc -> RescaleInPlace(c1);

    return 0;
}

It produce an error with message Removing last element of DCRTPoly object renders it invalid!.
I believe the message could be made more descriptive!

[Maokami]

Maybe related to #351?