[Bug]: Cant start training with best optuna trail

[rclarsfull]

🐛 Bug

load_trial() checks if the trail i is None if so i takes the best trail.
This can´t be reacht throw read_hyperparameters() becaus it checks this:

if self.storage and self.study_name and self.trial_id:
            print("Loading from Optuna study...")

To Reproduce

python rl_zoo3/train.py \
  --algo ppo \
  --env MergeEnv-v2 \
  --storage sqlite:///logs/mergeenv_optuna.db \
  --study-name MergeEventOptimizev1 \
  -P 

This will ignore the optuna study becaus not trail number is given.

Relevant log output / Error message

System Info

No response

Checklist

• I have checked that there is no similar issue in the repo
• I have read the SB3 documentation
• I have read the RL Zoo documentation
• I have provided a minimal and working example to reproduce the bug
• I've used the markdown code blocks for both code and stack traces.