mgcp-client: Always mark client as UP if keepalive request-interval disabled

In the previous logic, if "keepalive request-interval" was disabled
(value 0, default), then if the client was configured to send a DLCX on
startup it would end up in state UP or DOWN depending on whether the MGW
answered to that request.
As a result, an MGW that wouldn't answer would be left forever in DOWN
state since it would have been selected no more and there would be a
keepalive configured to re-mark it as UP.

Fixes: 563386e8bbf0bc6d9050d87f79208d6784e219cf
Related: SYS#6481
Change-Id: I290f7436f48418ee25179951359c76208796e279
---
M src/libosmo-mgcp-client/mgcp_client.c
1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index 677a4f3..b0ccfe7 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -951,16 +951,16 @@
 		some_dlcx_sent = true;
 	}
 
-	if (!some_dlcx_sent) {
-		if (mgcp->actual.keepalive.req_interval_sec > 0) {
+	if (mgcp->actual.keepalive.req_interval_sec > 0) {
+		if (!some_dlcx_sent) {
 			/* Attempt an immediate probe to find out if link is UP or DOWN: */
 			osmo_timer_schedule(&mgcp->keepalive_tx_timer, 0, 0);
-		} else {
-			/* Assume link is UP by default, so that this MGW can be selected: */
-			mgcp->conn_up = true;
 		}
+		/* else: keepalive_tx_timer was already scheduled (if needed) down in the stack during Tx DLCX above */
+	} else {
+		/* Assume link is UP by default, so that this MGW can be selected: */
+		mgcp->conn_up = true;
 	}
-	/* else: keepalive_tx_timer was already scheduled (if needed) down in the stack during Tx DLCX above */
 
 	if (mgcp->actual.keepalive.timeout_sec > 0)
 		osmo_timer_schedule(&mgcp->keepalive_rx_timer, mgcp->actual.keepalive.timeout_sec, 0);

