Partially revert "Implement perfect forward secrecy for MTProto (#4618)"

This partially reverts commit 5a3a94eb51.
It should be re-introduced once the rest of comments are addressed.

Session changes are kept for the future, even if unused for now,
as there may be people who have already upgraded their session.

telethon/client/messages.py

@@ -923,13 +923,7 @@ class MessageMethods:
                 effect=message_effect_id
             )
 
-        try:
-            result = await self(request)
-
-        except errors.rpcerrorlist.AuthKeyPermEmptyError as e:
-            await self._sender._reconnect(e)
-            result = await self(request)
-
+        result = await self(request)
         if isinstance(result, types.UpdateShortSentMessage):
             message = types.Message(
                 id=result.id,

telethon/client/telegrambaseclient.py

@@ -262,8 +262,7 @@ class TelegramBaseClient(abc.ABC):
             base_logger: typing.Union[str, logging.Logger] = None,
             receive_updates: bool = True,
             catch_up: bool = False,
-            entity_cache_limit: int = 5000,
-            store_tmp_auth_key_on_disk: bool = True
+            entity_cache_limit: int = 5000
     ):
         if not api_id or not api_hash:
             raise ValueError(
@@ -289,7 +288,7 @@ class TelegramBaseClient(abc.ABC):
         # Determine what session object we have
         if isinstance(session, (str, pathlib.Path)):
             try:
-                session = SQLiteSession(str(session), store_tmp_auth_key_on_disk=store_tmp_auth_key_on_disk)
+                session = SQLiteSession(str(session))
             except ImportError:
                 import warnings
                 warnings.warn(
@@ -433,7 +432,6 @@ class TelegramBaseClient(abc.ABC):
             auto_reconnect=self._auto_reconnect,
             connect_timeout=self._timeout,
             auth_key_callback=self._auth_key_callback,
-            tmp_auth_key_callback=self._tmp_auth_key_callback,
             updates_queue=self._updates_queue,
             auto_reconnect_callback=self._handle_auto_reconnect
         )
@@ -563,7 +561,6 @@ class TelegramBaseClient(abc.ABC):
             return
 
         self.session.auth_key = self._sender.auth_key
-        self.session.tmp_auth_key = self._sender.tmp_auth_key
         await utils.maybe_async(self.session.save())
 
         try:
@@ -786,14 +783,6 @@ class TelegramBaseClient(abc.ABC):
         self.session.auth_key = auth_key
         await utils.maybe_async(self.session.save())
 
-    def _tmp_auth_key_callback(self: 'TelegramClient', tmp_auth_key):
-        """
-        Callback from the sender whenever it needed to generate a
-        new temporary authorization key. This means we are not authorized.
-        """
-        self.session.tmp_auth_key = tmp_auth_key
-        self.session.save()
-
     # endregion
 
     # region Working with different connections/Data Centers