Drop qtBefore483() helper method

No longer needed with Qt 5.

client.cpp

@@ -355,22 +355,8 @@ void Client::destroyClient()
     deleteClient(this);
 }
 
-// DnD handling for input shaping is broken in the clients for all Qt versions before 4.8.3
-// NOTICE do not query the Qt version macro, this is a runtime problem!
-// TODO KDE5 remove this 
-static inline bool qtBefore483()
-{
-    QStringList l = QString(qVersion()).split(".");
-    // "4.x.y"
-    return l.at(1).toUInt() < 5 && l.at(1).toUInt() < 9 && l.at(2).toUInt() < 3;
-}
-
 void Client::updateInputWindow()
 {
-    static bool brokenQtInputHandling = qtBefore483();
-    if (brokenQtInputHandling)
-        return;
-
     QRegion region;
 
     if (!noBorder()) {