When calculating the combined stream flow state
for a period, don't consider stopped streams.
Fixes switching to the next period in DASH streams
with multiple video/audio/subtitle streams.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2684>
for (iter = period->streams; iter; iter = g_list_next (iter)) {
GstAdaptiveDemux2Stream *stream = iter->data;
+ /* Streams that are not running do not contribute
+ * to the flow */
+ if (stream->state == GST_ADAPTIVE_DEMUX2_STREAM_STATE_STOPPED)
+ continue;
+
if (stream->last_ret != GST_FLOW_NOT_LINKED) {
all_notlinked = FALSE;
if (stream->last_ret != GST_FLOW_EOS)