dash: fix `getSegments` for SegmentTemplate: it now should base itself on the beginning of a segment, not the beginning of the range wanted
dash: fix `getSegments` for SegmentTemplate: it now should base itself on the beginning of a segment, not the beginning of the range wanted

canalplus/rx-player,canalplus/rx-player,canalplus/rx-player,canalplus/rx-player,canalplus/rx-player