Fix get_file when the HTTP response has no Content-Length header (#19833)

Author: Grvzard

keras/src/utils/file_utils.py

@@ -270,9 +270,9 @@ def __init__(self):
                 self.finished = False
 
             def __call__(self, block_num, block_size, total_size):
+                if total_size == -1:
+                    total_size = None
                 if not self.progbar:
-                    if total_size == -1:
-                        total_size = None
                     self.progbar = Progbar(total_size)
                 current = block_num * block_size