fix error on no intersection

Author: hambsch

server/guppy/endpoints/endpoints.py

@@ -317,7 +317,7 @@ def get_point_value_from_layer(db: Session, layer_name: str, x: float, y: float)
             # get the value of the point
             point = wkt.loads(f'POINT ({x} {y})')
             values = tile_df[tile_df.intersects(point)].drop(columns=['geometry'])
-            if values.empty:
+            if not values.empty:
                 result = {'type': 'point value', 'layer_name': layer_name, 'value': values.to_dict(orient='records')[0]}
                 logger.info(f'get_point_value_from_raster 200 {time.time() - t}')
                 return result