Update DistUtils.cpp

GeoDaCenter#1751 (socio-weights creation) when "manhanttan distance" is selected, the bandwidth is computed with square root, which is not correct and should only be applied when "Euclidean distance" is selected

Weights/DistUtils.cpp

@@ -64,7 +64,8 @@ double DistUtils::GetMinThreshold()
     }
     delete[] nnIdx;
     delete[] dists;
-
+
+    if (ANN_DIST_TYPE == 1) return max_1nn_dist;
     return sqrt(max_1nn_dist);
 }