Update inferencer.py

inferencer.py

@@ -268,7 +268,7 @@ class UniPicV2Inferencer:
         width = width or self.image_size
 
         prompt = "Generate an image: " + prompt
-        negative_prompt = "Generate an image: " + negative_prompt or self.default_negative_prompt
+        negative_prompt = "Generate an image: " + negative_prompt if negative_prompt else self.default_negative_prompt
         inputs = self._prepare_text_inputs(prompt, negative_prompt)
         num_queries = self.conditioner.config.num_queries
         embeds = self._process_inputs(inputs, num_queries)