Fix run command for python dataflow example

examples/python-dataflow/run.sh

@@ -9,4 +9,4 @@ cd ../../../examples/python-dataflow
 # Dependencies
 pip install -r requirements.txt
 
-cargo run -p dora-coordinator --release -- run dataflow_without_webcam.yml
+cargo run -p dora-coordinator --release -- --run-dataflow dataflow_without_webcam.yml