fix(metric): process the null witness address

Author: Federico2014

framework/src/main/java/org/tron/core/metrics/node/NodeMetricManager.java

@@ -36,8 +36,10 @@ private void setNodeInfo(NodeInfo nodeInfo) {
 
     nodeInfo.setIp(Args.getInstance().getNodeExternalIp());
 
-    ByteString witnessAddress = ByteString.copyFrom(Args.getLocalWitnesses()
-        .getWitnessAccountAddress(CommonParameter.getInstance().isECKeyCryptoEngine()));
+    byte[] witnessAccountAddress = Args.getLocalWitnesses()
+        .getWitnessAccountAddress(CommonParameter.getInstance().isECKeyCryptoEngine());
+    ByteString witnessAddress =
+        witnessAccountAddress != null ? ByteString.copyFrom(witnessAccountAddress) : null;
     if (chainBaseManager.getWitnessScheduleStore().getActiveWitnesses().contains(witnessAddress)) {
       nodeInfo.setNodeType(1);
     } else {

framework/src/test/java/org/tron/core/zksnark/ShieldedReceiveTest.java

@@ -320,7 +320,8 @@ public void testBroadcastBeforeAllowZksnark()
   }
 
   /*
-   * generate spendproof, dataToBeSigned, outputproof example dynamically according to the params file
+   * generate spendproof, dataToBeSigned, outputproof example dynamically according to the params
+   * file
    */
   public String[] generateSpendAndOutputParams() throws ZksnarkException, BadItemException {
     librustzcashInitZksnarkParams();