Tor Browser Windows Installer overwrites bridge configuration

Bug description: Tor Browser Windows Installer overwrites bridge configuration

Steps to reproduce:

1. Install the stable Tor Browser release, and choose the usual Desktop where the Tor Browser file will be.
2. Open the Tor Browser and configure special bridges from bridges.torproject.org.
3. Close the Tor Browser and now run the Tor Browser installation for the alpha release, choose the default Desktop location.
4. Launch the Tor Browser and go to Onion Icon > Tor Network Settings.

Actual result: Bridge configuration was overwritten: there are no bridges.

Expected result: Bridge configuration shouldn't be overwritten by the installer.

Trac:
Username: blockflare