[Refactor](R18) Adapt to new aidge_cmp flag system

examples/export_ResNet18/resnet18.py

@@ -502,8 +502,9 @@ This option has to be passed to each node in order to be used within the Export
 (JConv, JPad, ...) that you can find in the "export_gen/operator_export" folder. 
 """
 
-for node in model.get_nodes():
-    node.attributes().aidge_cmp = AIDGE_CMP
+if AIDGE_CMP:
+    for node in model.get_nodes():
+        node.attributes().aidge_cmp = True
 
 # --------------------------------------------------------------
 # EXPORT THE MODEL