webvtt output has seconds as milliseconds

[Carl]

Summary of the bug:
How to reproduce:

% ffmpeg -i test.srt test.vtt
ffmpeg version 3.2.2
built on crosstool-ng-1.19.0
# i686-unknown-mingw32-gcc --version
i686-unknown-mingw32-gcc (crosstool-NG 1.19.0) 4.5.3
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

test.srt has:
1
00:00:00,000 --> 00:00:05,000
currently 00 minutes and 00 seconds en

converted to test.vtt has:
WEBVTT

00:00.000 --> 00:00.005
currently 00 minutes and 00 seconds en

This also happens when converting from a webvtt file in the proper format, to another webvtt file.

[Carl]

I have found this happens on windows 2003 only. The same compiled version works on a windows 7 x64 workstation.

[Carl Eugen Hoyos]

Please test current FFmpeg git head and provide the command line that outputs the broken file together with the complete, uncut console output to make this a valid ticket.

[mkver]

Can't reproduce. But I also didn't test Windows 2003.