Migration failure during reaction migration from gitea (go-gitea#13344)

* Migrating reactions is just not that important

A failure during migrating reactions should not cause failure of
migration.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* When checking issue reactions check the correct permission

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

Author: zeripath