module-raop: set min-latency correctly

I think we need to set this to the min-latency, not the latency
we will report in the sync messages.

See #3282

src/modules/module-raop-sink.c

@@ -1252,7 +1252,7 @@ static int rtsp_do_announce(struct impl *impl)
 				"a=min-latency:%d",
 				impl->session_id, ip_version, local_ip,
 				ip_version, host, frames, impl->info.rate,
-				impl->latency + RAOP_LATENCY_MIN);
+				RAOP_LATENCY_MIN);
 		if (!sdp)
 			return -errno;
 		break;