doc/gatt-api: Includes shall not be mandatory

It is perfectly fine to have a service without any Includes.
diff --git a/doc/gatt-api.txt b/doc/gatt-api.txt
index f58de23..60a997c 100644
--- a/doc/gatt-api.txt
+++ b/doc/gatt-api.txt
@@ -45,7 +45,7 @@
 			belongs to. Only present on services from remote
 			devices.
 
-		array{object} Includes [read-only]
+		array{object} Includes [read-only, optional]
 
 			Array of object paths representing the included
 			services of this service.
diff --git a/src/gatt-database.c b/src/gatt-database.c
index ce0e03f..24bcef5 100644
--- a/src/gatt-database.c
+++ b/src/gatt-database.c
@@ -1633,7 +1633,7 @@
 	char *obj;
 
 	if (!g_dbus_proxy_get_property(proxy, "Includes", &iter))
-		return false;
+		return true;
 
 	if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY)
 		return false;