Changes

tests: don't run osmotestconfig.py in distcheck

Call osmotestconfig.py from contrib/jenkins.sh, instead of running it as
part of the vty-tests. Previously it would run twice, once during
"make check" and another time during "make distcheck".

A follow-up patch sets state-dir to /var/lib/osmocom/osmo-sgsn in the
config that will actually be installed, and because the user that runs
the VTY tests typically does not have write access, a copy of the config
gets created in the tests directory that does not have this option.

This works fine with the VTY tests, except for osmotestconfig.py when
running as part of distcheck. I've tried to figure out why exactly it
does not work, but this isn't trivial because the script doesn't show
where the actual error is (OS#6456). It doesn't seem like a good use of
time to look into this further for now, instead it should be enough
running osmotestconfig.py once in contrib/jenkins.sh, and not have it
run as part of the VTY tests anymore.

Change-Id: I68e33a229a1cd035a9acef1210068af0e476bff3