Zotero links are broken due to wrong .desktop file

[malte-v]

First of all, thanks for taking on the effort to package Zotero! It works very well for me on aarch64-linux, but I've noticed that zotero:// links are not handled by Zotero, rendering them useless. I think this is because the correct .desktop file gets overwritten by a wrong one in the wrapFirefox function. As the creation of the desktop file by wrapFirefox is not really configurable, fixing this in a non-hacky way would probably require an upstream change to nixpkgs.

[malte-v]

A less elegant fix which doesn't require a change to nixpkgs is to use overrideAttrs to override the desktop item on the final, wrapped derivation.