BadUSB: command parser fix

[nminaylov]

What's new

• Fixed handling commands without arguments (fixes #2591)

Verification

• Check BadUSB test scripts

Checklist (For Reviewer)

• [ ] PR has description of feature/bug or link to Confluence/Jira task
• [ ] Description contains actions to verify feature/bugfix
• [ ] I've built this code, uploaded it to the device and verified feature/bugfix

[github-actions[bot]]

Compiled firmware for commit a66e32fa:

• 📦 Update package
• 📥 DFU file
• ☁️ Web/App updater