MySQL warning on upgrade 9 to 10

Seafile Server
3

The fix is to change the line

ALTER TABLE `WebUploadTempFiles` ADD INDEX IF NOT EXISTS `repo_id` (`repo_id`);

to

ALTER TABLE `WebUploadTempFiles` ADD INDEX `repo_id` (`repo_id`);

in

seafile-server-10.0.1/upgrade/sql/10.0.0/mysql/seafile.sql

If it still fails, you need to remove that line. (because the index exists already then)