mgcp_client: Use INET6_ADDRSTRLEN to store addresses in str format

Warning: This breaks libosmo-mgcp-cli ABI!

Related: SYS#4915
Change-Id: Ib778e9a72764103b52a462ea3c7fb56b23c1bcd6
diff --git a/include/osmocom/mgcp_client/mgcp_client.h b/include/osmocom/mgcp_client/mgcp_client.h
index d4dd2d9..8914cc2 100644
--- a/include/osmocom/mgcp_client/mgcp_client.h
+++ b/include/osmocom/mgcp_client/mgcp_client.h
@@ -75,7 +75,7 @@
 	char *body;
 	struct mgcp_response_head head;
 	uint16_t audio_port;
-	char audio_ip[INET_ADDRSTRLEN];
+	char audio_ip[INET6_ADDRSTRLEN];
 	unsigned int ptime;
 	enum mgcp_codecs codecs[MGCP_MAX_CODECS];
 	unsigned int codecs_len;