Update readme.txt

Fix stable tag

Author: kraftbj

readme.txt

@@ -4,7 +4,7 @@ Tags: fields, custom fields, meta, scf
 Requires at least: 6.0
 Tested up to: 6.7
 Requires PHP: 7.4
-.4.1-beta7
+Stable tag: 6.4.1-beta7
 License: GPLv2 or later
 License URI: https://www.gnu.org/licenses/gpl-2.0.html
 
@@ -84,4 +84,4 @@ This plugin builds upon and is a fork of the previous work done by the contribut
 == Upgrade Notice ==
 
 = 6.4.1-beta6 =
-Corrects issue where Options page would not display in wp-admin and a missing function from the Clone field.
+Corrects issue where Options page would not display in wp-admin and a missing function from the Clone field.