nixos/tests/virtualbox: Give VMs more memory.
nixos/tests/virtualbox: Give VMs more memory.

We previously had 1024 MB of memory to fit a VirtualBox VM with 512 MB
plus the memory needed of the VirtualBox host VM. That obviously won't
work for two VirtualBox VMs, which are used for testing networking
between two VirtualBox guests.

Now, we have 2048 MB on the qemu guest (the VirtualBox host) and 768 MB
for each VirtualBox guest. That should be enough to fit in two
VirtualBox guests (I hope).

Signed-off-by: aszlig <ee1aa092358634f9c53f01b5a783726c9e21b35a@redmoonstudios.org>

NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,triton/triton,NixOS/nixpkgs,SymbiFlow/nixpkgs,triton/triton,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,triton/triton,SymbiFlow/nixpkgs,triton/triton,triton/triton,triton/triton,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,triton/triton,SymbiFlow/nixpkgs,NixOS/nixpkgs,triton/triton,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs