portfolio: 0.68.3 -> 0.68.4

https://github.com/portfolio-performance/portfolio/releases/tag/0.68.4

pkgs/applications/office/portfolio/default.nix

···
 in
 stdenv.mkDerivation rec {
   pname = "PortfolioPerformance";
-  version = "0.68.3";
+  version = "0.68.4";
 
   src = fetchurl {
     url = "https://github.com/buchen/portfolio/releases/download/${version}/PortfolioPerformance-${version}-linux.gtk.x86_64.tar.gz";
-    hash = "sha256-7EQ/gKFflElga5LDwAkjPcqNl6HNtnAzno1ZGPBybJY=";
+    hash = "sha256-E4uVI2MJ2tD2wuAxxzCZSmNRbKTTzhi44c4ip7uEhCk=";
   };
 
   nativeBuildInputs = [