replay: just load one segment to start replaying (#22598)

selfdrive/ui/replay/replay.cc

@@ -128,12 +128,17 @@ void Replay::queueSegment() {
   // get the current segment window
   SegmentMap::iterator begin, cur, end;
   begin = cur = end = segments_.lower_bound(current_segment_);
+  if (cur != segments_.end() && cur->second == nullptr) {
+    // just load one segment on starting replay or seeking
+    end++;
+  } else {
     for (int i = 0; i < BACKWARD_SEGS && begin != segments_.begin(); ++i) {
       --begin;
     }
     for (int i = 0; i <= FORWARD_SEGS && end != segments_.end(); ++i) {
       ++end;
     }
+  }
 
   // load & merge segments
   for (auto it = begin; it != end; ++it) {