netsync: always call resetHeaderState on Syncmanager.New()

Since we're purely headers-first during ibd, we need to call
resetHeaderState regardless of whether or not we have more checkpmore
checkpoints.

netsync/manager.go

@@ -2305,12 +2305,10 @@ func New(config *Config) (*SyncManager, error) {
 	if !config.DisableCheckpoints {
 		// Initialize the next checkpoint based on the current height.
 		sm.nextCheckpoint = sm.findNextHeaderCheckpoint(best.Height)
-		if sm.nextCheckpoint != nil {
-			sm.resetHeaderState(&best.Hash, best.Height)
-		}
 	} else {
 		log.Info("Checkpoints are disabled")
 	}
+	sm.resetHeaderState(&best.Hash, best.Height)
 
 	// If we're at assume utreexo mode, build headers first.
 	if sm.chain.IsUtreexoViewActive() && sm.chain.IsAssumeUtreexo() {