Fixes the only exception, in razoring.
The code already does assert(PvNode || (alpha == beta - 1)), and it can be verified by studying the program flow that this is indeed the case, also for the modified line.
No functional change.
&& eval + razor_margin[depth / ONE_PLY] <= alpha)
{
if (depth <= ONE_PLY)
- return qsearch<NonPV, false>(pos, ss, alpha, beta);
+ return qsearch<NonPV, false>(pos, ss, alpha, alpha+1);
Value ralpha = alpha - razor_margin[depth / ONE_PLY];
Value v = qsearch<NonPV, false>(pos, ss, ralpha, ralpha+1);