git-svn: remove assertion that broke with older versions of svn

svn < 1.3.x would display changes to keywords lines as modified
if they aren't expanded in the working copy.  We already check
for changes against the git tree here, so checking against the
svn one is probably excessive.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

contrib/git-svn/git-svn.perl

@@ -567,7 +567,6 @@ sub precommit_check {
 sub svn_checkout_tree {
 	my ($svn_rev, $treeish) = @_;
 	my $from = file_to_s("$REV_DIR/$svn_rev");
-	assert_svn_wc_clean($svn_rev);
 	assert_tree($from);
 	print "diff-tree $from $treeish\n";
 	my $pid = open my $diff_fh, '-|';