Avoid NPE in maybeStartAllocation

Author: Max Hniebergall

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/inference/adaptiveallocations/AdaptiveAllocationsScalerService.java

@@ -434,7 +434,7 @@ public boolean maybeStartAllocation(TrainedModelAssignment assignment) {
         if (assignment.getAdaptiveAllocationsSettings() != null
             && assignment.getAdaptiveAllocationsSettings().getEnabled() == Boolean.TRUE
             && (assignment.getAdaptiveAllocationsSettings().getMinNumberOfAllocations() == null
-                || assignment.getAdaptiveAllocationsSettings().getMinNumberOfAllocations() == 0)) {
+                || Integer.valueOf(0).equals(assignment.getAdaptiveAllocationsSettings().getMinNumberOfAllocations()))) {
 
             // Prevent against a flurry of scale up requests.
             if (deploymentIdsWithInFlightScaleFromZeroRequests.contains(assignment.getDeploymentId()) == false) {