fix typo

Signed-off-by: lilinjie <lilinjie@uniontech.com>

Author: uniontech-lilinjie

Diff for: gssapi/sec_contexts.py

@@ -483,7 +483,7 @@ def delegated_creds(self) -> t.Optional[Credentials]:
         .. warning::
 
             This value will not be preserved across picklings.  These should
-            be separately exported and transfered.
+            be separately exported and transferred.
 
         """
         return self._delegated_creds