Fix Broken Error Message

Signed-off-by: Hassan Abouelela <hassan@hassanamr.com>

Author: HassanAbouelela

backend/routes/forms/form.py

@@ -78,7 +78,7 @@ async def patch(self, request: Request) -> JSONResponse:
         try:
             data = await request.json()
         except json.decoder.JSONDecodeError:
-            return JSONResponse("Expected a JSON body.", 400)
+            return JSONResponse({"error": "Expected a JSON body."}, 400)
 
         form_id = request.path_params["form_id"].lower()
         await discord.verify_edit_access(form_id, request)