small cave wall fix, new snake sprite and polished fjolarok post cutting east island out

src/server/config/maps/sewer/map.json

@@ -1,12 +1,4 @@
 { "backgroundcolor":"#32222e",
- "compressionlevel":0,
- "editorsettings":
-    {
-     "export":
-        {
-         "target":"."
-        }
-    },
  "height":120,
  "infinite":false,
  "layers":[
@@ -2346,7 +2338,7 @@
          "value":"[{\"x\":97,\"y\":87}]"
         }],
  "renderorder":"right-down",
- "tiledversion":"1.3.1",
+ "tiledversion":"1.2.5",
  "tileheight":8,
  "tilesets":[
         {