Update azure_sas_conn.py - fixing container_url typo (#2740)

### What problem does this PR solve?

Fixes #2739

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

rag/utils/azure_sas_conn.py

@@ -23,10 +23,10 @@ def __open__(self):
             pass
 
         try:
-            self.conn = ContainerClient.from_container_url(self.account_url + "?" + self.sas_token)
+            self.conn = ContainerClient.from_container_url(self.container_url + "?" + self.sas_token)
         except Exception as e:
             azure_logger.error(
-                "Fail to connect %s " % self.account_url + str(e))
+                "Fail to connect %s " % self.container_url + str(e))
 
     def __close__(self):
         del self.conn
@@ -77,4 +77,4 @@ def get_presigned_url(self, bucket, fnm, expires):
                 azure_logger.error(f"fail get {bucket}/{fnm}: " + str(e))
                 self.__open__()
                 time.sleep(1)
-        return
+        return