Fix vercel.json and index.js rename

Author: statico

api/index.js api/server.jsapi/index.js renamed to api/server.js

@@ -3,11 +3,11 @@
   "rewrites": [
     {
       "source": "/(.*)",
-      "destination": "/api/index"
+      "destination": "/api/server"
     }
   ],
   "functions": {
-    "api/index.js": {
+    "api/server.js": {
       "maxDuration": 30
     }
   }