Keep announcing the delivery-method in the capabilities

Even though we don't use delivery-method in our payloader, older versions of
the theora payloader in gstreamer required it. As such we need to keep this
around in the caps for backwards-compatibility.

This reverts part of 49463a37cbaa952e1401291f0a2623de6cab3880

Fixes #618940

gst/rtp/gstrtptheorapay.c

@@ -434,6 +434,7 @@ gst_rtp_theora_pay_finish_headers (GstBaseRTPPayload * basepayload)
       "width", G_TYPE_STRING, wstr,
       "height", G_TYPE_STRING, hstr,
       "configuration", G_TYPE_STRING, configuration,
+      "delivery-method", G_TYPE_STRING, "inline",
       /* don't set the other defaults 
        */
       NULL);