Remove the query
If a query is present, it is removed. An empty query is distinct from having no query.
assert( url( "http://www.example.com?id=42" ).remove_query().buffer() == "http://www.example.com" );
this->has_query() == false && this->params().empty()
query = *( pchar / "/" / "?" )
query-param = key [ "=" value ]
query-params = [ query-param ] *( "&" query-param )