Reproduction util: wrong command path

[Quentin Gallouédec]

Small issue:

$ python -m cleanrl_utils.reproduce --run openrlbenchmark/cleanrl/runs/c1y1qnz4

# run the following
python3 -m venv venv
source venv/bin/activate
pip install -r https://api.wandb.ai/files/openrlbenchmark/cleanrl/c1y1qnz4/requirements.txt
curl -OL https://api.wandb.ai/files/openrlbenchmark/cleanrl/c1y1qnz4/code/cleanrl/ppo_atari.py
python /fsx/costa/cleanrl/cleanrl/ppo_atari.py --track --env-id BreakoutNoFrameskip-v4 --seed 3

it should be

- python /fsx/costa/cleanrl/cleanrl/ppo_atari.py --track --env-id BreakoutNoFrameskip-v4 --seed 3
+ python ppo_atari.py --track --env-id BreakoutNoFrameskip-v4 --seed 3