Change index from position to activate following issue comment [https://github.com/thelia/thelia/pull/332#issuecomment-41174056]

setup/thelia.sql

@@ -867,7 +867,7 @@ CREATE TABLE `module`
     `updated_at` DATETIME,
     PRIMARY KEY (`id`),
     UNIQUE INDEX `code_UNIQUE` (`code`),
-    INDEX `idx_module_position` (`position`)
+    INDEX `idx_module_activate` (`activate`)
 ) ENGINE=InnoDB CHARACTER SET='utf8';
 
 -- ---------------------------------------------------------------------

setup/update/2.0.1.sql

@@ -6,7 +6,7 @@ UPDATE `config` SET `value`='2.0.1' WHERE `name`='thelia_version';
 UPDATE `config` SET `value`='' WHERE `name`='thelia_extra_version';
 
 
-ALTER TABLE `module` ADD INDEX `idx_module_position` (`position`);
+ALTER TABLE `module` ADD INDEX `idx_module_activate` (`activate`);
 
 
 SET FOREIGN_KEY_CHECKS = 1;