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 stdenv, 4 fetchpatch, 5 fetchurl, 6 SDL, 7 SDL_mixer, 8 bulletml, ··· 47 ''; 48 49 buildInputs = [ 50 SDL 51 SDL_mixer 52 bulletml
··· 3 stdenv, 4 fetchpatch, 5 fetchurl, 6 + libGL, 7 + libGLU, 8 SDL, 9 SDL_mixer, 10 bulletml, ··· 49 ''; 50 51 buildInputs = [ 52 + libGL 53 + libGLU 54 SDL 55 SDL_mixer 56 bulletml