Checkmk Werk 14936: logwatch: fix validation for REWRITE state

ID: 14936 Title: logwatch: fix validation for REWRITE state Component: Checks & agents Level: 1 Class: Bug fix Version: 2.2.0i1 The validation fot the REWRITE state in the Text logfiles rule (logwatch plugin) was erroring out when the patterns contained a reference to the previously matched groups. This werk fixes the issue.