Remove FSF mailing address

It has changed in the past, and these days, anyone can get a copy of the
LGPL via the web rather than by post.

Like 657a122 (Remove FSF mailing address) in libabc by Josh Tripplet,
but let the FSF website in which the license can be found.
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index ac6b71a..54bde73 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -14,8 +14,7 @@
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <assert.h>