Can't add tags in tour

[cellio]

https://meta.codidact.com/questions/277092

A user taking the tour got stuck at the tags, getting the message "The results could not be loaded" when trying to add them. The user eventually found out how to continue through the tour, but this error was confusing.

[sau226]

It looks like we query a tag set with id of -1 inside that aspect of the tour. We should probably double check any special casing we have for that tag set or create it in seeds if it does not already exist.

[Taeir]

Fixed by #841 / #856