Running mock debugger gives error during activation

[Jeroen Scheeres]

Os: Windows 10
NodeJs version: 14.6

Reproduction steps:

1. Start extension
2. Open test.md in extension development host
3. Debug the markdown file (hit F5)
4. Error

Error message:
Activating extension 'andreweinand.mock-debug' failed: a DebugAdapterDescriptorFactory can only be registered from the extension that defines the 'mock' debugger..

I also tested it on Ubuntu with NodeJs 14.13.1. It works on Ubuntu.

[Andre Weinand]

This is VS Code problem microsoft/vscode#118562 which is fixed in VS Code 1.54.3.