Wait 30 seconds after the node starts before computing our online accounts.

This allows some time for initial online account lists to be retrieved, and reduces the chances of the same nonce being computed twice.

src/main/java/org/qortal/controller/OnlineAccountsManager.java

@@ -57,6 +57,8 @@ public class OnlineAccountsManager {
     private static final long ONLINE_ACCOUNTS_TASKS_INTERVAL = 10 * 1000L; // ms
     private static final long ONLINE_ACCOUNTS_BROADCAST_INTERVAL = 5 * 1000L; // ms
 
+    private static final long INITIAL_SLEEP_INTERVAL = 30 * 1000L;
+
     // MemoryPoW
     public final int POW_BUFFER_SIZE = 1 * 1024 * 1024; // bytes
     public int POW_DIFFICULTY = 18; // leading zero bits
@@ -118,14 +120,23 @@ public class OnlineAccountsManager {
         // Expire old online accounts signatures
         executor.scheduleAtFixedRate(this::expireOldOnlineAccounts, ONLINE_ACCOUNTS_TASKS_INTERVAL, ONLINE_ACCOUNTS_TASKS_INTERVAL, TimeUnit.MILLISECONDS);
 
-        // Send our online accounts
-        executor.scheduleAtFixedRate(this::sendOurOnlineAccountsInfo, ONLINE_ACCOUNTS_BROADCAST_INTERVAL, ONLINE_ACCOUNTS_BROADCAST_INTERVAL, TimeUnit.MILLISECONDS);
-
         // Request online accounts from peers
         executor.scheduleAtFixedRate(this::requestRemoteOnlineAccounts, ONLINE_ACCOUNTS_BROADCAST_INTERVAL, ONLINE_ACCOUNTS_BROADCAST_INTERVAL, TimeUnit.MILLISECONDS);
 
         // Process import queue
         executor.scheduleWithFixedDelay(this::processOnlineAccountsImportQueue, ONLINE_ACCOUNTS_QUEUE_INTERVAL, ONLINE_ACCOUNTS_QUEUE_INTERVAL, TimeUnit.MILLISECONDS);
+
+        // Sleep for some time before scheduling sendOurOnlineAccountsInfo()
+        // This allows some time for initial online account lists to be retrieved, and
+        // reduces the chances of the same nonce being computed twice
+        try {
+            Thread.sleep(INITIAL_SLEEP_INTERVAL);
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // Send our online accounts
+        executor.scheduleAtFixedRate(this::sendOurOnlineAccountsInfo, ONLINE_ACCOUNTS_BROADCAST_INTERVAL, ONLINE_ACCOUNTS_BROADCAST_INTERVAL, TimeUnit.MILLISECONDS);
     }
 
     public void shutdown() {