refs #5599 Fixing minor bug using '/' as the base of the backup dir.
refs #5599 Fixing minor bug using '/' as the base of the backup dir.

kbauskar/Percona-TokuBackup,dbpercona/Percona-TokuBackup,kbauskar/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,dbpercona/Percona-TokuBackup,tplavcic/Percona-TokuBackup,percona/Percona-TokuBackup,dbpercona/Percona-TokuBackup,tplavcic/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,percona/Percona-TokuBackup,tplavcic/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,guiquanz/Percona-TokuBackup,guiquanz/Percona-TokuBackup,percona/Percona-TokuBackup,tplavcic/Percona-TokuBackup,guiquanz/Percona-TokuBackup,kbauskar/Percona-TokuBackup,dbpercona/Percona-TokuBackup,guiquanz/Percona-TokuBackup,kbauskar/Percona-TokuBackup,percona/Percona-TokuBackup