Cleanup TestMainWindow, trying to make sure virtual members can be seen
I don't know why suse_tumbleweed_qt66 CI is sometimes giving a compilation error saying 'undefined reference to `vtable for TestMainWindow'.
This commit changes the TestMainWindow, trying to make sure that the compiler has access(?) to all virtual members. It is more an "empirical" solution than an actual one, but it improves code readability IMO anyway.
Signed-off-by: Tarcisio Fischer tarcisio.fischer@codethink.co.uk