delete negative prompt if base model is flux

src/routes/api/generate/+server.ts

@@ -38,7 +38,7 @@ export async function POST({ request, cookies } : RequestEvent) {
   })
 
   if (model?.base_model === "black-forest-labs/FLUX.1-dev") {
-    delete generation.negative_prompt
+    delete generation.parameters.negative_prompt
   }
 
   const response = await fetch(process.env.SECRET_INFERENCE_API_URL + "/models/" + generation?.model?.id, {