Remove bogus portion of unit test

In Qt 4, QSignalSpy didn't *really* connect to the signal it was
spying on. See the "we need to connect the signal somewhere in order
for D-Bus to enable the rules" comments.

In Qt 5, it connects, which rendered this section of the test bogus:
since the signal is still connected, the QSignalSpy will notice that
fact and will not be empty. This is passing due to a false
positive. The upcoming fix breaks it, so we need to remove it.

Change-Id: Ic8fbf7d0e941403e97149f5bc392334a52c66ab1
Reviewed-by: Lorn Potter <lorn.potter@jollamobile.com>

tests/auto/dbus/qdbusabstractinterface/tst_qdbusabstractinterface.cpp

@@ -1017,18 +1017,6 @@ void tst_QDBusAbstractInterface::followSignal()
     // now the signal must have been received:
     QCOMPARE(s.size(), 1);
     QVERIFY(s.at(0).size() == 0);
-    s.clear();
-
-    // disconnect the signal
-    disconnect(p.data(), SIGNAL(voidSignal()), &QTestEventLoop::instance(), 0);
-
-    // emit the signal again:
-    emit targetObj.voidSignal();
-    QTestEventLoop::instance().enterLoop(2);
-    QVERIFY(!QTestEventLoop::instance().timeout());
-
-    // and now it mustn't have been received
-    QVERIFY(s.isEmpty());
 
     // cleanup:
     con.interface()->unregisterService(serviceToFollow);