Fixed #29329 -- Made datetime logging from runserver more consistent.

Setting default_msec_format=None will make it the same, unfortunately
it's not supported by Python, see https://bugs.python.org/issue40300.

django/utils/log.py

@@ -160,6 +160,8 @@ class RequireDebugTrue(logging.Filter):
 
 
 class ServerFormatter(logging.Formatter):
+    default_time_format = '%d/%b/%Y %H:%M:%S'
+
     def __init__(self, *args, **kwargs):
         self.style = color_style()
         super().__init__(*args, **kwargs)

tests/logging_tests/tests.py

@@ -605,4 +605,4 @@ class LogFormattersTests(SimpleTestCase):
 
         with patch_django_server_logger() as logger_output:
             logger.info(log_msg)
-            self.assertRegex(logger_output.getvalue(), r'^\[[-:,.\s\d]+\] %s' % log_msg)
+            self.assertRegex(logger_output.getvalue(), r'^\[[/:,\w\s\d]+\] %s\n' % log_msg)