Extension .webm not accepted for video files (input)

[tomsam]

I try to convert a .webm file to one of the supported output format (using Format junkie).

Webm is listed in the output format selection box, so I guess, it should be accepted as input format as well
(the underlying ffmpeg and others support webm, too)

Steps:

1. select Add Video files
2a. press Add
2b. The "Choose video Files" dialog is opened
3. navigate to the source directory

Now, the .webm files are not displayed, most likely, because the .webm extension is not in the "Files of type" list.

Questions:

Is this a bug or a missing feature?
Can I configure "format junkie" so that input files of type .webm are accepted?