Spike - Fix document selector in the Extension

[DonJayamanne]

Following warnings are logged when running Unit Tests:

Extension 'ms-python.python' uses a document selector without scheme. Learn more about this: https://go.microsoft.com/fwlink/?linkid=872305

[DonJayamanne]

Upgrading to P1 as this is a warning displayed by VS Code.

[RichieChoo]

how do you fix it,I met it in my extension

[Abbyyan]

how do you fix it,I met it in my extension。 Thanks a lot ~