Update to a hopefully more future proof FSF address

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/hw/e1000_hw.h b/hw/e1000_hw.h
index 9993a7d..9bd8a4b 100644
--- a/hw/e1000_hw.h
+++ b/hw/e1000_hw.h
@@ -13,8 +13,7 @@
   more details.
 
   You should have received a copy of the GNU General Public License along with
-  this program; if not, write to the Free Software Foundation, Inc.,
-  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+  this program; if not, see <http://www.gnu.org/licenses/>.
 
   The full GNU General Public License is included in this distribution in
   the file called "COPYING".