zoom-us: use regular qt5
zoom-us: use regular qt5

`zoom-us` used to be not compatible with the current qt5 version
provided by `libsForQt5.callPackage`, but it is by now.

To avoid downloading a different qt (or even building it), point it back
to the generic `libsForQt5.callPackage`.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs