tap_tool_dispatcher: keep existing behaviour by not removing empty directories
tap_tool_dispatcher: keep existing behaviour by not removing empty directories

Different behaviour noticed by Christian Hofstaedtler <christian@hofstaedtler.name>

hashar/jenkins-debian-glue,kartikm/jenkins-debian-glue,jbfavre/jenkins-debian-glue,tonin/jenkins-debian-glue,webtrekk-kane/jenkins-debian-glue,kartikm/jenkins-debian-glue,bmiklautz/jenkins-debian-glue,mika/jenkins-debian-glue,mika/jenkins-debian-glue,webtrekk-kane/jenkins-debian-glue,tonin/jenkins-debian-glue,jbfavre/jenkins-debian-glue,linuxmaniac/jenkins-debian-glue,wikimedia/operations-debs-jenkins-debian-glue,hashar/jenkins-debian-glue,linuxmaniac/jenkins-debian-glue,bmiklautz/jenkins-debian-glue,wikimedia/operations-debs-jenkins-debian-glue