quick fixing time format for jenkins plugin xunit

[DEvil0000]

jenkins xunit plugin expects only 3 decimal digits not 4. 4 does not make too much sense anyways.

see also jenkinsci/xunit-plugin#172

[victorolinasc]

Hi @DEvil0000 ! Thanks a lot for your contribution!

This problem with a standard in JUnit always comes back to haunt us.

I am ok with having only 3 (not 4... I thought I checked that when creating this library...) decimals. I am only thinking about breaking compatibility of the output. Not sure if someone is "expecting" this to be 4 instead of 3 decimals.

As cruel as this might seem, perhaps we should add this as a configuration? Wdyt?

[DEvil0000]

In my opinion 3,6 and 9 digits after the decimal point make more sense then 4. I would not worry to much about breaking things here. However of course an configurable amount would help everyone.