tests: monitor: fix up test case breakage

tests: monitor: fix up test case breakage

Monitor test fails:

 echo: running tests from file set-simple.t
 echo output differs!
  -add element ip t portrange { 1024-65535 }
   add element ip t portrange { 100-200 }
  +add element ip t portrange { 1024-65535 }
  +# new generation 510 by process 129009 (nft)

I also noticed -j mode did not work correctly, add missing json annotations
in set-concat-interval.t while at it.

Signed-off-by: Florian Westphal <fw@strlen.de>