Lets fix this

controller.py

@@ -213,7 +213,7 @@ def groq_chat(csv_url: str, question: str):
 
         except Exception as e:
             error_message = str(e)
-            if "429" in error_message:
+            if error_message != "":
                 logger.warning("Rate limit exceeded. Switching to next API key.")
                 with current_groq_key_lock:
                     current_groq_key_index += 1
@@ -266,7 +266,8 @@ def langchain_csv_chat(csv_url: str, question: str, chart_required: bool):
 
         except Exception as e:
             error_message = str(e)
-            if "429" in error_message:
+            # if "429" in error_message:
+            if error_message != "":
                 with current_langchain_chart_lock:
                     current_langchain_chart_key_index = (current_langchain_chart_key_index + 1) % len(groq_api_keys)
                     logger.warning(f"Rate limit exceeded. Switching to next API key: {groq_api_keys[current_langchain_chart_key_index]}")
@@ -404,7 +405,8 @@ def groq_chart(csv_url: str, question: str):
 
         except Exception as e:
             error = str(e)
-            if "429" in error:
+            # if "429" in error:
+            if error != "":
                 with current_groq_chart_lock:
                     current_groq_chart_key_index = (current_groq_chart_key_index + 1) % len(groq_api_keys)
             else:
@@ -747,7 +749,7 @@ def langchain_csv_chart(csv_url: str, question: str, chart_required: bool):
 
         except Exception as e:
             error_message = str(e)
-            if "429" in error_message:
+            if error_message != "":
                 with current_langchain_chart_lock:
                     current_langchain_chart_key_index = (current_langchain_chart_key_index + 1) % len(groq_api_keys)
                     logger.warning(f"Rate limit exceeded. Switching to next API key: {groq_api_keys[current_langchain_chart_key_index]}")