packImages doesn't use the output name

[screwdycrow]

Description of the bug

When i try to apply the packImages script using some combination of strings in the output name field, the script saves the pack with the format type as name isntead.
ex: png.png

If i leave this blank it saves the pack with the name package which i guess is the right behaviour.

Steps to reproduce the bug

select any number of images, open packImages, enter any string as output name hit apply.

[oumad]

The fixed script can be downloaded directly from the repo for now.