hard fork in mantenance

Author: Yrp

src/main/java/org/tron/common/utils/ForkController.java

@@ -105,7 +105,7 @@ public synchronized void update(BlockCapsule blockCapsule) {
       return;
     }
 
-    if (stats == null) {
+    if (stats == null || stats.length != witnesses.size()) {
       stats = new byte[witnesses.size()];
     }