utils: jenkins-jnlp-connect.sh: Fix start up script

utils: jenkins-jnlp-connect.sh: Fix start up script

The jenkins-jnlp-connect.sh script is meant to be executed from the
$jenkinshome directory. The monit script was configured to enter a
different directory before starting the jenkins script which always
resulted in a broken start-up phase like this:

"This script needs to be run from the jenkins users home dir"

We fix this by entering the $jenkinshome directory before starting up
the jenkins script.

Change-Id: If0f65417f07a7fa9328f9adcd1ca1a1a3bc530ed
Signed-off-by: Markos Chandras <mchandras@suse.de>