network: independently initalize state->out_stream

The struct state->out_stream.ssrc is initalized by first initalizing
state->in_stream and then copying state->in_stream over to
state->out_stream. This works as long as no pointers to other objects
are added to struct mgcp_rtp_stream_state but we may add pointers to
struct mgcp_rtp_stream_state in the future.

- Initalize out_stream and in_stream independently from each other

Change-Id: I5deb27e609448ee0b9f7034e644ae96f1e57887a
Related: OS#2517
diff --git a/src/libosmo-mgcp/mgcp_network.c b/src/libosmo-mgcp/mgcp_network.c
index 6923b97..49e51a1 100644
--- a/src/libosmo-mgcp/mgcp_network.c
+++ b/src/libosmo-mgcp/mgcp_network.c
@@ -511,7 +511,9 @@
 		state->in_stream.last_tsdelta = 0;
 		state->packet_duration =
 		    mgcp_rtp_packet_duration(endp, rtp_end);
-		state->out_stream = state->in_stream;
+		state->out_stream.last_seq = seq - 1;
+		state->out_stream.ssrc = state->patch.orig_ssrc = ssrc;
+		state->out_stream.last_tsdelta = 0;
 		state->out_stream.last_timestamp = timestamp;
 		state->out_stream.ssrc = ssrc - 1;	/* force output SSRC change */
 		LOGP(DRTP, LOGL_INFO,