update gpl 2 mailing address in source files

src/zm_threaddata.cpp

@@ -14,7 +14,7 @@
 // 
 // 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 // 
 
 template class ThreadData<bool>;