revise soft limit test

- don't bail out of the loop if clients are exceeded, just count incidents
- verbosely describe expectations and results
4 jobs for fix-fetchlimit in 11 minutes and 13 seconds (queued for 10 seconds)
Status Job ID Name Coverage
  Build
passed #2663
linux docker
build:debian:sid:amd64

00:05:03

passed #2664
linux docker
build:debian:sid:i386

00:05:36

 
  Test
passed #2665
linux docker
test:debian:sid:amd64

00:05:35

passed #2666
linux docker
test:debian:sid:i386

00:05:34