splitmuxsink: Increment fragment_id even if no fragment location was provided
requested to merge slomo/gst-plugins-good:splitmuxsink-increment-fragment-id-on-no-location into master
Applications might handle locations and generally configuration of the sink by themselves instead of having splitmuxsink set the location on the sink. Nonetheless it makes sense to increment the fragment_id that is passed to the signal so that applications know which fragment is requested.