Fixed export summary misplaced commas

[anonymous2585]

When exporting a glb, the summary has strange comma placement that bug me.

Before:

With this PR:

[cla-assistant-unity]

All committers have signed the CLA.

[atteneder]

I approve :)

First I need you to sign the CLA, only then I can go ahead and merge internally.

Thanks

[anonymous2585]

I signed the CLA right after creating this PR, but it wasn't able to link with my github account.

This is now fixed ;)

[atteneder]

Excellent. After some touch-ups around that area it's now going through CI. Expect it to land in the next release.