VSCode doesn't "see" an `api_key` when using `import_cfg` and still always prompts for _WakaTime API key_

[vorburger]

Due to #387 I have attempted to set it up as shown here, that is:

1. ~/.wakatime.cfg with a import_cfg = ~/.wakatime/wakatime_secret.cfg (as per the documentation)
2. ~/.wakatime/wakatime_secret.cfg with an api_key = waka_...

But this VSCode extension doesn't seem to "see" this. https://wakatime.com/plugins/status doesn't show the ping, and it still always prompts for a WakaTime API key at each start-up...