### Short description of the issue Deprecation warning with PHP 8.1: PHP Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in https://github.com/processwire/processwire/blob/a3cc73bd87c3fed53a2afd52f36acd568df588ff/wire/modules/PagePaths.module#L638 ### Expected behavior No warnings ### Actual behavior Warnings ### Steps to reproduce the issue install PagePaths module on PHP >= 8 ### Setup/Environment * ProcessWire version: 3.0.200 and latest dev * (Optional) PHP version: 8.1