Fix heuristics bumping (according to Armin's comments).

org.sat4j.core/src/main/java/org/sat4j/minisat/core/Solver.java

@@ -611,9 +611,9 @@ public class Solver<D extends DataStructureFactory>
                 // Trace reason for p
                 for (int j = 0; j < preason.size(); j++) {
                     int q = preason.get(j);
-                    this.order.updateVar(q);
                     if (!seen[q >> 1]) {
                         seen[q >> 1] = true;
+                        this.order.updateVar(q);
                         if (this.voc.getLevel(q) == decisionLevel()) {
                             counter++;
                             this.order.updateVarAtDecisionLevel(q);