fixed redirect, so that it does not display credentials after editing

opt/post.php

@@ -65,7 +65,8 @@ function answer_redirect($sub, $css, $post_id, $settings)
 	}
 
 	if ( ( $settings['enable_tripcodes'] == TRUE ) &&
-	     ( $_POST['combination'] == $_POST['combination_hidden'] ) ) { 
+	     ( $_POST['combination'] == $_POST['combination_hidden'] ) &&
+	     ( !empty($_POST['combination']) ) ) { 
 	    header( "refresh:10;url=/s/$sub/$css$random_string" );
 	    // we wait 10 seconds with the redirection
 	    $credentials = $_POST['combination'];