Restore missing line to copyright notice

Commit 12c9423832 in May 2003 accidentally removed the last line of
the copyright notice in getopt.c. Put it back.

src/port/getopt.c

@@ -26,6 +26,7 @@
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
  */
 
 #include "c.h"