/*
 * call-seq:
 *   easy.local_port_range = fixnum or nil            => fixnum or nil
 *
 * Set the local port range that will be used for the following +perform+
 * calls. This is a number (between 0 and 65535) that determines how far
 * libcurl may deviate from the supplied +local_port+ in order to find
 * an available port.
 *
 * If you set +local_port+ it's also recommended that you set this, since
 * it is fairly likely that your specified port will be unavailable.
 *
 * This option is ignored if compiled against libcurl < 7.15.2.
 */
static VALUE ruby_curl_easy_local_port_range_set(VALUE self, VALUE local_port_range) {