Filesystem service time should have a space between number and unit, too

[Ulrich Windl]

It seems most or all of monit status output shows a blank between the number and the unit, but service time of Filesystem does not.

The output is like 0.000ms/operation (of which....

If the overall message seems to be too long, I’d suggest to leave out the `of which `.

[Tildeslash]

fix issue #1018

→ <<cset 62a014d0f394>>