moving plans across projects does not rename log files (artifacts).

moving a plan from project A to project B does not rename the build log files.

./xml-data/builds/A-HEAD/download-data/build_logs/A-HEAD-1.log

is moved to

./xml-data/builds/B-HEAD/download-data/build_logs/A-HEAD-1.log

the UI tries to link to download/B-HEAD/build_logs/B-HEAD-1.log

and throws an exception.