argyllcms: unset AR

Commit 093cc00cdd9d8cf31ecce5bc1dd3645c460a1b98 sets the AR environment variable
by default, but this causes the argyllcms Makefile to use the wrong command.

+2
+2
pkgs/tools/graphics/argyllcms/default.nix
··· 84 substituteInPlace Makefile --replace "-j 3" "-j $NIX_BUILD_CORES" 85 # Remove tiff, jpg and png to be sure the nixpkgs-provided ones are used 86 rm -rf tiff jpg png 87 ''; 88 89 buildInputs = [
··· 84 substituteInPlace Makefile --replace "-j 3" "-j $NIX_BUILD_CORES" 85 # Remove tiff, jpg and png to be sure the nixpkgs-provided ones are used 86 rm -rf tiff jpg png 87 + 88 + unset AR 89 ''; 90 91 buildInputs = [