Make sure Session is always stopped upon exceptions in Client.get_file

pyrogram/client/client.py

@@ -2696,13 +2696,17 @@ class Client:
             )
 
             session.start()
-
+            try:
                 session.send(
                     functions.auth.ImportAuthorization(
                         id=exported_auth.id,
                         bytes=exported_auth.bytes
                     )
                 )
+            except Exception as e:
+                session.stop()
+                raise e
+
         else:
             session = Session(
                 dc_id,