fix no max_tokens in payload when the vision model name does not contain 'vision'.

app/client/platforms/openai.ts

@@ -190,7 +190,7 @@ export class ChatGPTApi implements LLMApi {
       };
 
       // add max_tokens to vision model
-      if (visionModel && modelConfig.model.includes("preview")) {
+      if (visionModel) {
         requestPayload["max_tokens"] = Math.max(modelConfig.max_tokens, 4000);
       }
     }