[ServerRequest] Host header is not set when URI has one
[ServerRequest] Host header is not set when URI has one

> You can opt-in to preserving the original state of the Host header by passing true for the second ($preserveHost) argument. When this argument is set to true, the returned request will not update the Host header of the returned message -- unless the message contains no Host header.

**unless the message contains no Host header.** So $preserveHost MUST be ignored if message does not have a Host header

jguittard/zend-diactoros,mnapoli/zend-diactoros,deepfreeze/zend-diactoros,mtymek/zend-diactoros,localheinz/zend-diactoros