WebRequest.cpp modifications to prevent exception that reboot ESP32

[SilvestreArduino]

WebRequest.cpp modifications to prevent exception that reboot ESP32:

In the master version, AsyncWebServerRequest::_removeNotInterestingHeaders() produce a exception in if(!_interestingHeaders.containsIgnoreCase(header->name().c_str())){ _headers.remove(header); } sentence.

Guru Meditation Error occurred due to a LoadProhibited exception. This type of error happens when the CPU tries to dereference a pointer that is either NULL or invalid.

Copilot suggested a modification in lines 181-188 of Webrequest.cpp and now it works fine.