Update gradio_app.py

gradio_app.py

@@ -58,7 +58,7 @@ def generate_answer(request: str, max_tokens: int = 256, language: str = "en", c
     logs = f"Request: {request}\nMax tokens: {max_tokens}\nLanguage: {language}\nCustom prompt: {custom_prompt}\n"
     try:
         maxTokens = max_tokens if 16 <= max_tokens <= 256 else 64
-        if isinstance(custom_prompt, str):
+        if isinstance(custom_prompt, str) and len(custom_prompt.strip()) > 1 and custom_prompt.strip() not in ['', None, ' ']:
             userPrompt = custom_prompt.replace("{prompt}", request)
         else:
             userPrompt = prompt.replace("{prompt}", request)