bsc_msc_ip.c: Create the GSM network earlier, send the reset on each connection

Create the GSM network at the end of the init, send the
GSM reset on each reconnection and close a small window
when we would send a SCCP msg before being authenticated.

For that we have introduced an authenticated into the bsc_msc
struct and will manage it inside the bsc_msc_ip.c

openbsc/include/openbsc/bsc_msc.h

@@ -29,6 +29,7 @@
 struct bsc_msc_connection {
 	struct write_queue write_queue;
 	int is_connected;
+	int is_authenticated;
 	const char *ip;
 	int port;