Find below code in qa-config.php file of root directory.
/*
$QA_CONST_PATH_MAP = array(
'questions' => 'topics',
'categories' => 'sections',
'users' => 'contributors',
'user' => 'contributor',
);
*/
here will be the code (below */)
$QA_CONST_PATH_MAP = array(
'category' => '',
);