[4.4] check for valid referrer

[heelc29]

Summary of Changes

check if $_SERVER['HTTP_REFERER'] is valid before call Uri::isInternal()

Testing Instructions

• login as super user in backend
• visit https://example.tl/administrator/index.php?option=com_admin&view=sysinfo&format=text (note: link is without token!)
• check php warnings (PHP >= 8.1 required)

Actual result BEFORE applying this Pull Request

PHP Deprecated: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in libraries/src/Uri/Uri.php on line 243

Expected result AFTER applying this Pull Request

No deprecation warning

Link to documentations

Please select:

• No documentation changes for docs.joomla.org needed
• No documentation changes for manual.joomla.org needed

[Quy]

I have tested this item ✅ successfully on 432c681

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[viocassel]

I have tested this item ✅ successfully on 432c681

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/42599.}

[alikon]

RTC

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/42599.}