[JENKINS-42376] - Add executor name on Unexpected exception. (#2970)

* Add executor name on Unexpected exception.

* Add a colon after job name

core/src/main/java/hudson/model/Executor.java

@@ -444,7 +444,7 @@ public class Executor extends Thread implements ModelObject {
             LOGGER.log(FINE, getName()+" interrupted",e);
             // die peacefully
         } catch(Exception | Error e) {
-            LOGGER.log(SEVERE, "Unexpected executor death", e);
+            LOGGER.log(SEVERE, getName()+": Unexpected executor death", e);
         } finally {
             if (asynchronousExecution == null) {
                 finish2();