git svn: log removals of empty directories

This also adds a test case for:
  "git svn: Don't create empty directories whose parents were deleted"
which was the reason we found this bug in the first place.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
diff --git a/git-svn.perl b/git-svn.perl
index bdd1f96..5a52068 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -3891,11 +3891,11 @@
 		}
 		print "\tD\t$gpath/\n" unless $::_q;
 		command_close_pipe($ls, $ctx);
-		$self->{empty}->{$path} = 0
 	} else {
 		$self->{gii}->remove($gpath);
 		print "\tD\t$gpath\n" unless $::_q;
 	}
+	$self->{empty}->{$path} = 0;
 	undef;
 }