Upgrade notification to Firefox 4.0.3 in the Unsafe Browser
_Originally created by @intrigeri on [#8694 (Redmine)](https://public-redmine-archive.tails.boum.org/code/issues/8694)_
On a fresh Tails 1.2.2 booted from ISO, after starting the Unsafe
Browser, I get a notification suggesting me to upgrade to Firefox 4.0.3.
Feature Branch: bugfix/8694-disable-unsafe-browser-update-check
### Related issues
- **Related to** tails/tails#8702
issue