NullReferenceException in Server.Completion

[jakebailey]

Seeing this one at the top now.

   at Microsoft.Python.LanguageServer.Implementation.Server.Completion(CompletionParams params, CancellationToken cancellationToken)
   at Microsoft.Python.LanguageServer.Implementation.LanguageServer.Completion(JToken token, CancellationToken cancellationToken)

[MikhailArkhipov]

This should be fixed in #837 (IC exception)

[jakebailey]

The latest version has that merged, so this is some other nullref. Not really sure what it could be, given it's supposedly happening in that function directly.