git-svn: Fix a typo and add a comma in an error message in git-svn

Signed-off-by: David Reiss <dreiss@facebook.com>
Acked-by: Eric Wong <normalperson@yhbt.net>

git-svn.perl

@@ -391,7 +391,7 @@ sub cmd_set_tree {
 sub cmd_dcommit {
 	my $head = shift;
 	git_cmd_try { command_oneline(qw/diff-index --quiet HEAD/) }
-		'Cannot dcommit with a dirty index.  Commit your changes first'
+		'Cannot dcommit with a dirty index.  Commit your changes first, '
 		. "or stash them with `git stash'.\n";
 	$head ||= 'HEAD';
 	my @refs;