Fix css selector to append gif toolbar button back

[MinhPhu0304]

Hello @N1ck, this is just an attempt from me trying to fix this extension. Vend is not the same without it

Github just rolled out a bunch of frontend change and it broke this extension

Proof that it works on my machine

PS I don't know what I'm doing so all feedback are welcomed 😅

[MinhPhu0304]

Thanks for that, just applied suggestion. I can soon use gif again 🥳