Creating gloss images is broken

[ocrasborn]

Both the automatic generation of gloss images, and the button for "Create Citation Form Image from Current Video" (in the edit mode) seem to be broken. (For the new dataset IS_WFD2007, I saw that on the server, there was not yet a folder under glossimage/. Creating that folder didn't solve the issue. However, it doesn't work for dataset ISL either, and for that dataset the folder had already been generated.)