Clean up data for un-used tags / taggings for Issues and MergeRequests
In d45a6b29, we removed acts_as_taggable_on in Issue and MergeRequest, however it seems that we still have data in these tables :
- tags
- taggings
Looks like the data has long been migrated to labels in db/migrate/20140729152420_migrate_taggable_labels.rb
See also #21399 (closed)
Edited by Thong Kuah