Deprecation Message on PHP 8.1: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated

[mrothauer]

Browser-Detect version: 4.5.1

Calling Browser::isMobile() triggers a deprecation message on PHP 8.1 (PHP 8.0 worked fine)

strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
League\Pipeline\FingersCrossedProcessor::process() /vendor/league/pipeline/src/FingersCrossedProcessor.php](vendor/league/pipeline/src/FingersCrossedProcessor.php), line 11
League\Pipeline\Pipeline::process() /vendor/league/pipeline/src/Pipeline.php](vendor/league/pipeline/src/Pipeline.php), line 34
hisorange\BrowserDetect\Parser::process() /vendor/hisorange/browser-detect/src/Parser.php](vendor/hisorange/browser-detect/src/Parser.php), line 210
hisorange\BrowserDetect\Parser::parse() /vendor/hisorange/browser-detect/src/Parser.php](vendor/hisorange/browser-detect/src/Parser.php), line 176
hisorange\BrowserDetect\Parser::detect() /vendor/hisorange/browser-detect/src/Parser.php](vendor/hisorange/browser-detect/src/Parser.php), line 140
hisorange\BrowserDetect\Parser::__call() /vendor/hisorange/browser-detect/src/Parser.php](vendor/hisorange/browser-detect/src/Parser.php), line 97
hisorange\BrowserDetect\Parser::__callStatic() /vendor/hisorange/browser-detect/src/Parser.php](vendor/hisorange/browser-detect/src/Parser.php), line 125