Proxy: split configured header names and values. Previously, each configured header was represented in one of two ways, depending on whether or not its value included any variables. If the value didn't include any variables, then it would be represented as as a single script that contained complete header line with HTTP/1.1 delimiters, i.e.: "Header: value\r\n" But if the value included any variables, then it would be represented as a series of three scripts: first contained header name and the ": " delimiter, second evaluated to header value, and third contained only "\r\n", i.e.: "Header: " "$value" "\r\n" This commit changes that, so that each configured header is represented as a series of two scripts: first contains only header name, and second contains (or evaluates to) only header value, i.e.: "Header" "$value" or "Header" "value" This not only makes things more consistent, but also allows header name and value to be accessed separately. Signed-off-by: Piotr Sikora <piotrsikora@google.com>

uwsgi_param  QUERY_STRING       $query_string;
uwsgi_param  REQUEST_METHOD     $request_method;
uwsgi_param  CONTENT_TYPE       $content_type;
uwsgi_param  CONTENT_LENGTH     $content_length;

uwsgi_param  REQUEST_URI        $request_uri;
uwsgi_param  PATH_INFO          $document_uri;
uwsgi_param  DOCUMENT_ROOT      $document_root;
uwsgi_param  SERVER_PROTOCOL    $server_protocol;
uwsgi_param  REQUEST_SCHEME     $scheme;
uwsgi_param  HTTPS              $https if_not_empty;

uwsgi_param  REMOTE_ADDR        $remote_addr;
uwsgi_param  REMOTE_PORT        $remote_port;
uwsgi_param  SERVER_PORT        $server_port;
uwsgi_param  SERVER_NAME        $server_name;