don't always show regeneration message

src/logic/future_moves.rs

@@ -301,7 +301,7 @@ impl FutureMoves {
             self.set_root_idx_raw(curr_board_idx);
             false
         } else {
-            if self.config.print {
+            if self.config.print && !self.arena.is_empty() {
                 println!("regenerating arena from board");
             }
             self.set_root_from_board(*board);