Disable startDiagnosis test temporarily

That test and isRunning test are tightly coupled and there is more
testing necessary first to avoid an infinite-loop in testIsRunning. It
is unclear what happens if checkForConcurrentException is called twice.

Change-Id: I08f0d211e67b042d8b7d18b2d49054bdae2f965e
Signed-off-by: Denis Knoepfle <denis.knoepfle@sap.com>