aptly-api postrm: do not remove potentially valuable data

debian/aptly-api.postrm

@@ -4,10 +4,6 @@ set -e
 
 case "$1" in
     purge|remove|upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)
-	# only remove /var/lib/aptly-api on purge
-	if [ "${1}" = "purge" ] ; then
-	    rm -rf /var/lib/aptly-api
-	fi
     ;;
 
     *)