all: g_hash_table_add doesn't return a value before 2.40

src/nm-bus-manager.c

@@ -873,8 +873,12 @@ nm_bus_manager_register_object (NMBusManager *self,
 	 * stable -- because the path is the identifier for the object in this
 	 * situation. */
 
+#if GLIB_CHECK_VERSION(2, 40, 0)
 	if (!g_hash_table_insert (priv->exported, (gpointer) path, object))
 		g_return_if_reached ();
+#else
+	g_hash_table_insert (priv->exported, (gpointer) path, object);
+#endif
 
 	nm_assert_exported (self, path, object);