mgcp_client: do not print (null) when address is ANY

When the address is set to ANY, the address string is NULL. The log then
prints "(null)" where the address normaly would be. This looks odd, lets
print "(any)" instead.

Change-Id: I2ea138827ee5b9f40d352bf594364ee930520609
diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index 440cd96..225b1ee 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -824,7 +824,8 @@
 		/* Choose a new port number to try next */
 		LOGP(DLMGCP, LOGL_NOTICE,
 		     "MGCPGW failed to bind to %s:%u, retrying with port %u\n",
-		     mgcp->actual.local_addr, mgcp->actual.local_port, mgcp->actual.local_port + 1);
+		     mgcp->actual.local_addr ? mgcp->actual.local_addr : "(any)", mgcp->actual.local_port,
+		     mgcp->actual.local_port + 1);
 		mgcp->actual.local_port++;
 	}
 
@@ -892,8 +893,9 @@
 	if (rc < 0) {
 		LOGP(DLMGCP, LOGL_FATAL,
 		     "Failed to initialize socket %s:%u -> %s:%u for MGCP GW: %s\n",
-		     mgcp->actual.local_addr, mgcp->actual.local_port,
-		     mgcp->actual.remote_addr, mgcp->actual.remote_port, strerror(errno));
+		     mgcp->actual.local_addr ? mgcp->actual.local_addr : "(any)", mgcp->actual.local_port,
+		     mgcp->actual.remote_addr ? mgcp->actual.local_addr : "(any)", mgcp->actual.remote_port,
+		     strerror(errno));
 		goto error_close_fd;
 	}