fix: translation error when passing empty user messages to certain models.. (#1612)

src/renderer/src/providers/OpenAIProvider.ts

@@ -279,6 +279,9 @@ export default class OpenAIProvider extends BaseProvider {
   async translate(message: Message, assistant: Assistant, onResponse?: (text: string) => void) {
     const defaultModel = getDefaultModel()
     const model = assistant.model || defaultModel
+    if (!message.content) {
+        message.content = ' '
+    }
     const messages = [
       { role: 'system', content: assistant.prompt },
       { role: 'user', content: message.content }