WP Optimize Premium 3.7.1

* FIX: Incorrect static method calling causes parse Error in PHP 5.6.36
* FIX: WebP - Trailing slash file creation issue in PHP 8
* FIX: PHP warning in cache rules file
* FIX: Asynchronous google fonts loaded twice
* TWEAK: Conditional Tags anchor tag fix

* FIX: Fix a fatal error that could occur in 3.2.4 if settings had not been saved

* FEATURE: Minify: Pre-generate assets
* FIX: Cache - 'Purge cache permissions' setting does not allow additional roles to access the purge cache tool
* TWEAK: Make smush details button work in media modal window
* TWEAK: Do not show overhead in red when the amount is small
* TWEAK: Avoid PHP Notices caused by "upgrader_process_complete" action