Amend comment on shutil.move in download_worker

os.renames cannot move across drives/partitions on any platform.

that is why shutil.move is used, because the OS allotted temp file could
possibly be on another drive or partition.

Also fix code formatting on new import statements.

pyrogram/client/client.py

@@ -35,9 +35,7 @@ from queue import Queue
 from signal import signal, SIGINT, SIGTERM, SIGABRT
 from threading import Event, Thread
 import tempfile
-
 import shutil
-
 import errno
 
 from pyrogram.api import functions, types
@@ -599,7 +597,7 @@ class Client:
                         else:
                             os.makedirs(os.path.dirname(file_name), exist_ok=True)
 
-                        # avoid errors moving between drives on windows
+                        # avoid errors moving between drives/partitions etc.
                         shutil.move(tmp_file_name, os.path.join(download_directory, file_name))
                     except OSError as e:
                         log.error(e, exc_info=True)