Fixing check continuos integration

Author: SeqLaz

libqfieldsync/utils/file_utils.py

@@ -255,6 +255,9 @@ def update_symbol_to_project_assets(
 
     def update_symbol_path_assets(symbol):
         """Updates the path of a symbol layer."""
+        if symbol is None:
+            return
+
         for symbol_layer in symbol.symbolLayers():
             if isinstance(
                 symbol_layer, (QgsSvgMarkerSymbolLayer, QgsRasterMarkerSymbolLayer)