[FLINK-4137] Tell Akka to shut down the JVM on fatal errors

This closes apache#2205

Author: rmetzger

flink-runtime/src/main/scala/org/apache/flink/runtime/akka/AkkaUtils.scala

@@ -144,7 +144,7 @@ object AkkaUtils {
       ConfigConstants.DEFAULT_AKKA_LOG_LIFECYCLE_EVENTS)
 
     val jvmExitOnFatalError = if (
-      configuration.getBoolean(ConfigConstants.AKKA_JVM_EXIT_ON_FATAL_ERROR, false)){
+      configuration.getBoolean(ConfigConstants.AKKA_JVM_EXIT_ON_FATAL_ERROR, true)){
       "on"
     } else {
       "off"