List iot hub after selecting subscription would fail randomly

[lirenhe]

Repo step:
Open new window of vscode, select iothub, then select subscription.
sometimes, the list of iothub is not listed. It happens more often if you just open a new VS code.

Note: the problem happened randomly. In most cases, it works fine.

[formulahendry]

This issue is from VS Code. Bug is reported to vscode repo: microsoft/vscode#48879

[formulahendry]

Have a workaround fix: #86