search for Latte desktop file in more generic way

--there are distros that do not return /usr/share/applications
as their first global path for desktop files. It is better to not
just search for the "applications" path but rather the desktop
file also to make sure that we use the first one found.

BUG:412612
FIXED-IN:0.9.4

app/settings/universalsettings.cpp

@@ -268,7 +268,7 @@ void UniversalSettings::setAutostart(bool state)
     //! end of removal of old autostart file
 
     QFile autostartFile(QDir::homePath() + "/.config/autostart/org.kde.latte-dock.desktop");
-    QFile metaFile(Layouts::Importer::standardPath("applications", false)+"/org.kde.latte-dock.desktop");
+    QFile metaFile(Layouts::Importer::standardPath("applications/org.kde.latte-dock.desktop", false));
 
     if (!state && autostartFile.exists()) {
         //! the first time that the user disables the autostart, this is recorded