This fix work only after applying other patch (but fix an issue that exist on master) (24519)
Bug: When you go to the kcm cursor, if you go hover a theme the "real" cursor change to show a preview. After applying a new theme the preview don't work anymore before you change the cursor size.
In order to work we need a call to setTheme that is done by setCursorSize.
Currently the if (m_currentSize == size) prevent the call to setTheme, so I removed it and removed the unused signal