Update nixos-unstable

channels/nixos-unstable/channel.json

 {
   "ref": "refs/heads/nixos-unstable",
   "url": "https://github.com/NixOS/nixpkgs/",
-  "rev": "1dc37370c489b610f8b91d7fdd40633163ffbafd",
-  "date": "2020-10-27T01:29:36+01:00",
-  "path": "/nix/store/i9xlaxqbdb027slfbr9ymq9xw050llm9-nixpkgs",
-  "sha256": "1qvfxf83rya7shffvmy364p79isxmzcq4dxa0lkm5b3ybicnd8f4",
+  "rev": "2247d824fe07f16325596acc7faa286502faffd1",
+  "date": "2020-11-21T20:51:51+01:00",
+  "path": "/nix/store/yrgidsgfh1bprf9aggvz6gz1m4pnb3g5-nixpkgs",
+  "sha256": "09jzdnsq7f276cfkmynqiaqg145k8z908rlr0170ld1sms1a83rw",
   "fetchSubmodules": false,
   "deepClone": false,
   "leaveDotGit": false