appsrc: Wake up the create() function on caps changes

This allows the new caps to be sent downstream as soon as possible
instead of having to wait for the next buffer/buffer list.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/840>

gst-libs/gst/app/gstappsrc.c

@@ -1457,6 +1457,9 @@ gst_app_src_set_caps (GstAppSrc * appsrc, const GstCaps * caps)
     }
     gst_queue_array_push_tail (priv->queue, new_caps);
     gst_caps_replace (&priv->last_caps, new_caps);
+
+    if ((priv->wait_status & STREAM_WAITING))
+      g_cond_broadcast (&priv->cond);
   }
 
   GST_OBJECT_UNLOCK (appsrc);