git-svn.perl: perform deletions before anything else

git-svn.perl: perform deletions before anything else

If we delete a file and recreate it as a directory in a single commit,
we have to tell the server about the deletion first or else we'll get
"RA layer request failed: Server sent unexpected return value (405
Method Not Allowed) in response to MKCOL request"

Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Acked-by: Eric Wong <normalperson@yhbt.net>