Remove 25890_install.vdf after initial run; Delete leader portraits

While all the other fixes were valid at various points, the current issue for Intel gen10 and higher is resolved with adding - OPENSSL_ia32cap = 0x20000000 to the launch options in Steam. This fix was found on the GoG support for the title and confirmed to resolve the immediate crash upon launching the game from the launcher. Removing the vdf file prevents dotNet 2.0 from repeatedly attempting to install every launch and removing the leader portraits resolves the delay in changing leaders for units.