999 chops of suffix zero, 000 allows for the milliseconds to be always
printed with 3 chars. This makes the log the printed with the same
columns.

(partial logs below)

2018-11-13T21:13:28.249Z [INFO] [::1]
2018-11-13T21:13:48.414Z [INFO] [::1]
2018-11-13T21:13:49.1Z [INFO] [::1]

vs:

2018-11-13T21:20:22.262Z [INFO] [::1]
2018-11-13T21:20:22.436Z [INFO] [::1]
2018-11-13T21:20:22.608Z [INFO] [::1]
Signed-off-by: Miek Gieben <miek@miek.nl>