[TIMOB-13163] iOS: HTTPClient setRequestHeader does not work for some headers

Problem description

When I create a HTTPClient and use the setRequestHeader method this doesn't have effect for some headers. Headers that are nog being set: Accept-Encoding (in the code example i set this to 'gzip, deflate', in the sniffer the value is 'gzip'.) Connection (in the code example i set this to 'Keep-Alive', in the sniffer the value is 'close'.) (maybe there are more headers that are not being set but I tested with this 2 headers) Headers that are set correctly: Accept Accept-Language User-Agent In the attachment you can find the code as well as a screenprint of fiddler (the http sniffer tool i use)