target link was being created incorrectly
target link was being created incorrectly

If the target symbolic link already existed, an invalid link in target
was created to java/target. Fixed by checking if the link exists before
creating it

Change-Id: Ie53f396820e0e0022a949799b2b433b5ae11c4d1

sapcc/monasca-thresh,openstack/monasca-thresh,sapcc/monasca-thresh,openstack/monasca-thresh,stackforge/monasca-thresh,openstack/monasca-thresh,stackforge/monasca-thresh