rrootage: fix build

commit 7aeac03 (PR #386495) dropped libX11 and libGLU from propagatedBuildInputs in SDL_compat, and #389106 pointed SDL to SDL_compat, which broke this build

Hydra fail: https://hydra.nixos.org/build/292771916

Grimmauld 2caa23f6 2341cd6a

+4
+4
pkgs/by-name/rr/rrootage/package.nix
··· 3 3 stdenv, 4 4 fetchpatch, 5 5 fetchurl, 6 + libGL, 7 + libGLU, 6 8 SDL, 7 9 SDL_mixer, 8 10 bulletml, ··· 47 49 ''; 48 50 49 51 buildInputs = [ 52 + libGL 53 + libGLU 50 54 SDL 51 55 SDL_mixer 52 56 bulletml