null is not supported

haas-spim-benchmark/src/main/java/cz/it4i/fiji/haas_spim_benchmark/core/BenchmarkJobManager.java

@@ -97,9 +97,6 @@ public class BenchmarkJobManager {
 		}
 		
 		public synchronized CompletableFuture<JobState> getStateAsync(Executor executor) {
-			if(executor == null) {
-				return CompletableFuture.completedFuture(null);
-			}
 			if(running != null) {
 				return running;
 			}