Debug: backup openocd work area, fix crash after fresh debugger connect and continue

[skotopes]

What's new

• Debug: backup openocd work area, fix crash after fresh debugger connect and continue

Verification

• Flash firmware
• ./fbt debug and then disconnect
• Reconnect USB - no crash should happen

Checklist (For Reviewer)

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

[github-actions[bot]]

Compiled f7 firmware for commit 0a5aaf52:

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