Update config.json

Co-authored-by: Isaac Good <IsaacG@users.noreply.github.com>

Author: KasimKaizer

config.json

@@ -1178,19 +1178,6 @@
           "strings"
         ]
       },
-      {
-        "slug": "affine-cipher",
-        "name": "Affine Cipher",
-        "uuid": "cf62a3c5-af1a-4d05-a004-11b35eb79442",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 4,
-        "topics": [
-          "algorithms",
-          "cryptography",
-          "strings"
-        ]
-      },
       {
         "slug": "all-your-base",
         "name": "All Your Base",