Use rmdir argument or config parameter:
–rmdir
Only used with the dcommit, set-tree and commit-diff commands.
Remove directories from the SVN tree if there are no files left
behind. SVN can version empty directories, and they are not removed by
default if there are no files left in them. git cannot version empty
directories. Enabling this flag will make the commit to SVN act like
git.config key: svn.rmdir