Changed yakuake autostart to only start in KDE Plasma

plasma/autostart.nix

@@ -12,6 +12,11 @@
     description = "Automatically start Yakuake";
     after = ["graphical-session.target"];
     wantedBy = ["graphical-session.target"];
+
+    unitConfig = {
+      ConditionEnvironment = "XDG_CURRENT_DESKTOP=KDE";
+    };
+
     serviceConfig = {
       ExecStart = ["${pkgs.kdePackages.yakuake}/bin/yakuake"];