Fix: don't continue, if IPSec start commands failed.

src/nm-l2tp-service.c

@@ -963,7 +963,12 @@ nm_l2tp_start_ipsec(NML2tpPlugin *plugin,
 	rename(tmp_secrets, "/etc/ipsec.secrets");
 	sys += system("PATH=\"/sbin:/usr/sbin:/usr/local/sbin:$PATH\" ipsec secrets");
 	if (sys != 0)
-		g_warning("Possible error in IPSec setup.");
+		g_set_error (error,
+		             NM_VPN_PLUGIN_ERROR,
+		             NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+		             "%s",
+		             _("Possible error in IPSec setup."));
+		return FALSE;
 
 	g_message(_("ipsec ready for action"));
 	return TRUE;