Fix bug with resume

[savchenkoyana]

Hello, I noticed strange code behavior.

I ran training on coco128:

python train.py --name exp_coco128

trained for 2 epochs and then stopped.

Then ran:

python train.py --weights runs/train/exp_coco128/weights/last.pt

And the training continued from the 3rd epoch, although I didn't use --resume flag.
What's the point of --resume command if I resume my previous training without using it anyways?

I suggest calling smart_resume function only if resume == True. What do you think?

Thank you!

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improvement in handling resume training logic in YOLOv5.

📊 Key Changes

• Modified the train.py script, particularly the resume training functionality.
• Added a conditional check to ensure smart_resume is called only when resume flag is true.

🎯 Purpose & Impact

• 🎯 Purpose: To make the training resume process more robust and error-free by checking the resume flag before attempting to load previous training states.
• 💡 Impact: Users will experience smoother resumption of interrupted training sessions, leading to more efficient experimentation and model development. This change prevents unnecessary attempts to resume from a checkpoint when the user has not explicitly requested it, thus safeguarding against potential issues or confusion.

[github-actions]

👋 Hello @savchenkoyana, thank you for submitting a YOLOv5 🚀 PR! To allow your work to be integrated as seamlessly as possible, we advise you to:

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[glenn-jocher]

@savchenkoyana PR is merged. Thank you for your contributions to YOLOv5 🚀 and Vision AI ⭐