Fix docs string

Co-authored-by: Niko <onikolas@amazon.com>

airflow/providers/microsoft/azure/secrets/key_vault.py

@@ -168,7 +168,7 @@ def build_path(path_prefix: str, secret_id: str, sep: str = '-') -> str:
         :param secret_id: Name of the secret
         :param sep: Separator used to concatenate path_prefix and secret_id
         """
-        # when no prefix is given by default it adds sep for the key
+        # When an empty prefix is given, do not add a separator to the secret name
         if path_prefix == "":
             path = f'{secret_id}'
         else: