splitmuxsink: Don't accumulate more than 2 GOPs

Don't allow large amounts of data to queue up - we only need
the GOP we're writing, and the GOP we're accumulating.

gst/multifile/gstsplitmuxsink.c

@@ -872,7 +872,7 @@ check_queue_length (GstSplitMuxSink * splitmux, MqStreamCtx * ctx)
         splitmux->queued_gops <= 1) {
       allow_grow = TRUE;
     } else if (splitmux->state == SPLITMUX_STATE_COLLECTING_GOP_START &&
-        ctx->is_video) {
+        ctx->is_video && splitmux->queued_gops <= 1) {
       allow_grow = TRUE;
     }