Gets the value of header
name in this.
Use this for headers whose values are
not comma-delimited lists, and which therefore can only appear at most once in the headers.
For list-valued headers, use get_list.
If this does erroneously contain multiple copies of the header, it is not defined which one will be returned. (Ideally, it will return whichever one makes libsoup most compatible with other HTTP implementations.)
the header's value or