ipa: use AF_UNSPEC instead of AF_INET

To allow IPv6 use AF_UNSPEC. AF_UNSPEC allows to be IPv4 or IPv6
address at the same time.

TODO: check if osmo_sock_init() is also prefering IPv6
TODO: how to allow the user to specify if IPv4 or IPv6 should be taken.

Change-Id: I5b740c46a850b35f9012d7f78394f55408889136
diff --git a/src/input/ipa.c b/src/input/ipa.c
index 0f67dca..8609755 100644
--- a/src/input/ipa.c
+++ b/src/input/ipa.c
@@ -225,7 +225,7 @@
 	int ret;
 
 	link->state = IPA_CLIENT_LINK_STATE_CONNECTING;
-	ret = osmo_sock_init2(AF_INET, SOCK_STREAM, IPPROTO_TCP,
+	ret = osmo_sock_init2(AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP,
 			     link->local_addr, link->local_port,
 			     link->addr, link->port,
 			     OSMO_SOCK_F_BIND|OSMO_SOCK_F_CONNECT|OSMO_SOCK_F_NONBLOCK);
@@ -336,7 +336,7 @@
 {
 	int ret;
 
-	ret = osmo_sock_init(AF_INET, SOCK_STREAM, IPPROTO_TCP,
+	ret = osmo_sock_init(AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP,
 			     link->addr, link->port, OSMO_SOCK_F_BIND);
 	if (ret < 0)
 		return ret;