Issue Type: Bug
After typing something in the textarea on the description webview and clicking "Approve" or "Request Changes", the text remains in the text area
Extension version: 1.37.0
VS Code version: Code - Insiders 1.32.0-insider (d9f81c831c6e97cd9423ca7c85b7b6bf6e3d58cf, 2019-02-06T21:05:30.168Z)
OS version: Darwin x64 18.0.0