fix(monster): fix condition_immunities for Gelatinous Cube (#464)

Author: timpatullock

src/5e-SRD-Monsters.json

@@ -15968,9 +15968,9 @@
         "url": "/api/conditions/charmed"
       },
       {
-        "index": "blinded",
-        "name": "Blinded",
-        "url": "/api/conditions/blinded"
+        "index": "deafened",
+        "name": "Deafened",
+        "url": "/api/conditions/deafened"
       },
       {
         "index": "exhaustion",