Incompatibility with RSYNC >=3.2.4

[buvoli]

Remote rsync commands fail for rsync >=3.2.4 due to a change in arg protection (see release notes). As suggested by the release notes, a temporary fix is to run export RSYNC_OLD_ARGS=1 before running cjr. A more permanent solution would be to modify cjr so that the flag --old-args is applied for rsync >=3.2.4.