QNX host lookup: do not try to load libresolv.so, it is not there

Not trying to load the lib saves 30 - 50ms upon an apps' 1st host
lookup.

Task-number: QTBUG-30809
Change-Id: Id893cec09ff57494776625700c93f7efe96fcc6b
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>

src/network/kernel/qhostinfo_unix.cpp

@@ -92,7 +92,7 @@ static res_state_ptr local_res = 0;
 
 static void resolveLibrary()
 {
-#ifndef QT_NO_LIBRARY
+#if !defined(QT_NO_LIBRARY) && !defined(Q_OS_QNX)
     QLibrary lib(QLatin1String("resolv"));
     if (!lib.load())
         return;