BAC-281: remove old WikiaApiQueryConfGroups API module

Remove old API module.

```
May 17 10:21:05 ap-s23 apache2[819]: SQL (tryenisehir): 1146: Table 'tryenisehir.city_variables_pool' doesn't exist (10.8.50.66)
May 17 10:21:05 ap-s23 apache2[819]: SQL: invalid query: SELECT /* WikiaApiQueryConfGroups::execute 93.183.172.225 */  cv_group_id,cv_group_name  FROM `city_variables_pool` JOIN `city_variables_groups` ON cv_variable_group = cv_group_id JOIN `city_variables` ON cv_id = cv_variable_id  WHERE cv_city_id = '1588'
```