[15349] Fix NPE in Provisioner#update

bundles/es.core.p2/src/info/elexis/server/core/p2/internal/Provisioner.java

@@ -167,8 +167,7 @@ public class Provisioner implements IProvisioner {
 		ProvisioningSession session = new ProvisioningSession(agent);
 		List<IInstallableUnit> effectiveUpdates = updates.stream().map(ii -> ii.toUpdate).collect(Collectors.toList());
 		UpdateOperation updateOperation = new UpdateOperation(session, effectiveUpdates);
-
-		IStatus result = updateOperation.getResolutionResult();
+		IStatus result = updateOperation.resolveModal(monitor);
 		StatusUtil.logStatus("updateResolutionResult", log, result);
 		if (result.isOK()) {
 			ProvisioningJob job = updateOperation.getProvisioningJob(monitor);