Drop install-type appimages

src/configs/destinations.json

 {
     "bin": "$HOME/bin",
-    "appimages": "$HOME/.appimages",
     "downloads": "$HOME/Downloads",
     "documents": "$HOME/Documents",
     "pictures": "$HOME/Pictures",

src/handlers/xdgurl.cpp

@@ -152,10 +152,6 @@ void XdgUrl::_installDownloadedFile(QNetworkReply *reply)
             && Utility::Package::installProgram(temporaryFile.fileName(), path)) {
         result["message"] = QString("The program has been installed into " + destination);
     }
-    else if (type == "appimages"
-             && Utility::Package::installProgram(temporaryFile.fileName(), path)) {
-        result["message"] = QString("The Appimage has been installed into " + destination);
-    }
     else if ((type == "plasma_plasmoids" || type == "plasma4_plasmoids" || type == "plasma5_plasmoids")
              && Utility::Package::installPlasmapkg(temporaryFile.fileName(), "plasmoid")) {
         result["message"] = QString("The plasmoid has been installed");