VSCE Bug: basePath config is not support on Windows

Created by: abeatrix

• Sourcegraph version: VSCE v2.2.1
• Platform information: VS Code

The basePath config is currently not support on Windows

Steps to reproduce:

1. Make a search in the extension on Windows so that the basePath will be added to your User Setting automatically
2. Check your User Setting in VS Code

Expected behavior:

No error

Actual behavior:

Receive error about basePath does not match regex pattern

If would like immediate help on this, please email [email protected] (you can still create the issue, but there are not SLAs on issues like there are for support requests).