The relevant test is conducted by tst_Moc::warnOnVirtualSignal(),
added in 2009, <quote>
Fix Warning saying that signal cannot be made virtual
The test for virtual signal did not work.
But we cannot make an error right now or it might break existing code
(exemple in task 210879)
</quote> but without removing the #include, so we do still get a
warning about that when building tst_moc.
Pick-to: 6.2 6.1 5.15
Change-Id: I5ea18058f22bbd483d1ff18b0ca7b360f6674ed9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>