Remove dead code from qdbusintegrator.cpp

This code has been there since the initial public commit, but has no
effect.

Change-Id: Iae80ae22a363b3bd0e6cf7706619b38edc47790f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbusintegrator.cpp

@@ -1330,8 +1330,6 @@ bool QDBusConnectionPrivate::prepareHook(QDBusConnectionPrivate::SignalHook &hoo
         hook.midx = findSlot(receiver, normalizedName, hook.params);
     }
     if (hook.midx < minMIdx) {
-        if (hook.midx == -1)
-        {}
         return false;
     }