fixed not finding weights

perception_roi_server.py

@@ -34,7 +34,7 @@ from fastapi.responses import FileResponse, StreamingResponse, JSONResponse
 from ultralytics import YOLO
 
 DEFAULT_WEIGHTS = os.environ.get("YOLO_WEIGHTS", "yolov8s.pt")
-WEIGHTS_DIR = os.environ.get("WEIGHTS_DIR", "")
+WEIGHTS_DIR = os.environ.get("WEIGHTS_DIR", os.path.dirname(__file__))
 DEFAULT_CONF = float(os.environ.get("YOLO_CONF", "0.25"))
 DEFAULT_DEVICE = os.environ.get("YOLO_DEVICE", "auto")
 FAST_DETECT_SCALE = float(os.environ.get("FAST_DETECT_SCALE", "0.65"))