DOC: mention that %ms is left-padded with zeroes.
That's important to emit logs.
(cherry picked from commit 812c88ec126e8fc4fc0f7853f265594d03c63956)
diff --git a/doc/configuration.txt b/doc/configuration.txt
index e8d8b2a..1d95b5b 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -12381,7 +12381,7 @@
| | %hrl | captured_request_headers CLF style | string list |
| | %hs | captured_response_headers default style | string |
| | %hsl | captured_response_headers CLF style | string list |
- | | %ms | accept date milliseconds | numeric |
+ | | %ms | accept date milliseconds (left-padded with 0) | numeric |
| | %pid | PID | numeric |
| H | %r | http_request | string |
| | %rc | retries | numeric |