This update for gstreamer fixes the following issue:
- Fix a crash in gstreamer. (bsc#1097405)
GstDeviceProvider has a started_count private variable, start will add 1 to it and stop will subtract 1 from it.
However, current code forget to add 1 if it was already started, so if we start it twice and then stop it twice,
it will crash at the second stop call.