fix broken feed editor (is_private handling)

backend.php

@@ -1827,7 +1827,7 @@
 			$auth_login = db_escape_string($_POST["login"]);
 			$auth_pass = db_escape_string($_POST["pass"]);
 			$parent_feed = db_escape_string($_POST["pfeed"]);
-			$private = db_escape_string($_POST["private"]);
+			$private = db_escape_string($_POST["is_pvt"]);
 
 			if (strtoupper($upd_intl) == "DEFAULT")
 				$upd_intl = 0;

prefs.js

@@ -699,7 +699,7 @@ function feedEditSave() {
 		var purge_intl = document.getElementById("iedit_purgintl").value;
 		var fcat = document.getElementById("iedit_fcat");
 
-		var is_pvt = document.getElementById("iedit_is_pvt");
+		var is_pvt = document.getElementById("iedit_private");
 
 		if (is_pvt) {
 			is_pvt = is_pvt.checked;