test_dachshund fails for LOGQ = 48

[miha-stopar]

Increasing LOGQ to 48 causes the failure when running test_dachshund:

labrador/labrador.c

Line 1276 in 8b6626b

fprintf(stderr,"ERROR in verify(): Aggregated dot-product constraint doesn't hold\n");

At first we thought the cause might be the potential overflow here:

labrador/polz.c

Line 657 in 8b6626b

poly_quot_add(&k,&b.vec[i],&primes[i]); // TODO: Overflow possible for K > 8

but after fixing the code to avoid the potential overflow the issue was still there.

Not sure, perhaps the cause is the aggregation of the JL projection constraints as the code there relies heavily on LOGQ? Just looking into it, but some help would be welcome :)

The reason for increasing LOGQ is because we would like to benchmark the signature aggregation (in Lazer) for 10 000 signatures, but for this one needs to increase q.