"Loading" message not translated for Hierarchy and Groups tabs

[osma]

At which URL did you encounter the problem?

http://finto.fi/yso/fi/

What steps will reproduce the problem?

1. Use Skosmos in a non-English language
2. Go to vocabulary front page
3. Click on Hierarchy or Groups tab

What is the expected output? What do you see instead?

While the data loads, a "Loading" message is displayed, but it is always in English.
The alphabetical index tab has a similar, but translated message (e.g. "Ladataan sisältöä" in Finnish). Probably the same message could be used for other tabs as well.

What browser did you use? (eg. Firefox, Chrome, Safari, Internet explorer)