Fix Kuroko2::JobDefinition.search_by

[hogelog]

Kuroko2::JobDefinition.search_by doesn't work correct unless Kuroko2.config.table_name_prefix is empty.

Started GET "/definitions?utf8=%E2%9C%93&q=ghoege" for ::1 at 2016-11-09 12:04:44 +0900
Processing by Kuroko2::JobDefinitionsController#index as JS
  Parameters: {"utf8"=>"✓", "q"=>"ghoege"}
  Kuroko2::User Load (0.4ms)  SELECT  `kuroko2_users`.* FROM `kuroko2_users` WHERE `kuroko2_users`.`suspended_at` IS NULL AND `kuroko2_users`.`id` = 1 LIMIT 1
Unpermitted parameter: utf8
   (0.4ms)  SELECT DISTINCT `kuroko2_job_definition_tags`.`job_definition_id` FROM `kuroko2_job_definition_tags` INNER JOIN `kuroko2_tags` ON `kuroko2_tags`.`id` = `kuroko2_job_de
 WHERE (tags.name LIKE '%ghoege%')
Completed 500 Internal Server Error in 3ms (ActiveRecord: 0.8ms)


  
ActiveRecord::StatementInvalid (Mysql2::Error: Unknown column 'tags.name' in 'where clause': SELECT DISTINCT `kuroko2_job_definition_tags`.`job_definition_id` FROM `kuroko2_job_de
finition_tags` INNER JOIN `kuroko2_tags` ON `kuroko2_tags`.`id` = `kuroko2_job_definition_tags`.`tag_id` WHERE (tags.name LIKE '%ghoege%')):

Job definition search doesn't work.

Please review.

[eagletmt]

LGTM

[eisuke]

LGTM