flimflam: Don't crash if LockType/RetriesLeft are not specified.

src/device.c

Index: src/device.c
diff --git a/src/device.c b/src/device.c
index c226acb6adfd4b39f4c95bdac4e6740faf91ff88..886a0938e0d279923518441b58807b06be6aa468 100644
--- a/src/device.c
+++ b/src/device.c
@@ -431,12 +431,14 @@ static void append_ipconfig(DBusMessageIter *dict, void *arg)
 static void append_unlock_status(DBusMessageIter *dict, void *arg)
 {
 	struct connman_device *device = arg;
-	connman_dbus_dict_append_basic(dict, "LockType",
-				       DBUS_TYPE_STRING,
-				       &device->cellular.unlock_required);
-	connman_dbus_dict_append_basic(dict, "RetriesLeft",
-				       DBUS_TYPE_UINT32,
-				       &device->cellular.unlock_retries);
+	if (device->cellular.unlock_required)
+		connman_dbus_dict_append_basic(dict, "LockType",
+					       DBUS_TYPE_STRING,
+					       &device->cellular.unlock_required);
+	if (device->cellular.unlock_retries)
+		connman_dbus_dict_append_basic(dict, "RetriesLeft",
+					       DBUS_TYPE_UINT32,
+					       &device->cellular.unlock_retries);
 }
 
 static DBusMessage *get_properties(DBusConnection *conn, DBusMessage *msg,