Update optimum/exporters/openvino/convert.py

Co-authored-by: Ella Charlaix <80481427+echarlaix@users.noreply.github.com>

optimum/exporters/openvino/convert.py

@@ -139,7 +139,7 @@ def export(
         )
 
     if "diffusers" in str(model.__class__) and not is_diffusers_available():
-        raise ImportError("The package `diffusers` is required to export diffusion models to ONNX.")
+        raise ImportError("The package `diffusers` is required to export diffusion models to OpenVINO.")
 
     if stateful:
         # This will be checked anyway after the model conversion, but checking it earlier will save time for a user if not suitable version is used