Update repl.py

[Xplo8E]

Checklist

• [ ] Closing issues: #issue
• [ ] Mark this if you consider it ready to merge
• [ ] I've added tests (optional)
• [ ] I wrote some documentation

Description

In r2ai repl, when running system commands with !, this error is came.

adding import os fixed the issue

[trufae]

Thank you!