Ensure that RunControls ramp down asynchronously.

Since RunControls now ramp down asynchronously the plugin can
only report synchronous shut down if no RunControl/OutputPane
was present.

Task-number: QTCREATORBUG-18605
Change-Id: Ib8d1f857f85c74d4f18ecb85db537121a2275668
Reviewed-by: Orgad Shaneh <orgads@gmail.com>