cli: initialize connection list in do_device_connect()

The connection list may be required in nmc_secrets_requested() if
secrets are needed.

Fixes: 45fc268890

https://bugzilla.gnome.org/show_bug.cgi?id=767987
(cherry picked from commit bf7b9c60b6)

clients/cli/devices.c

@@ -1716,6 +1716,8 @@ do_device_connect (NmCli *nmc, int argc, char **argv)
 	nmc->nowait_flag = (nmc->timeout == 0);
 	nmc->should_wait++;
 
+	nmc->connections = nm_client_get_connections (nmc->client);
+
 	/* Create secret agent */
 	nmc->secret_agent = nm_secret_agent_simple_new ("nmcli-connect");
 	if (nmc->secret_agent)