gource: add missing libX11

Grimmauld e2970e59 5d2326a3

+2
+2
pkgs/by-name/go/gource/package.nix
··· 13 13 glew, 14 14 libGLU, 15 15 libGL, 16 + libX11, 16 17 boost, 17 18 glm, 18 19 tinyxml, ··· 43 44 SDL2_image 44 45 libGLU 45 46 libGL 47 + libX11 46 48 boost 47 49 glm 48 50 freetype