fix FSF address in sources/headers

Signed-off-by: Jaroslav Škarvada <jskarvad@redhat.com>
diff --git a/include/osmocom/core/linuxrbtree.h b/include/osmocom/core/linuxrbtree.h
index ef8bc15..d3f9fd1 100644
--- a/include/osmocom/core/linuxrbtree.h
+++ b/include/osmocom/core/linuxrbtree.h
@@ -14,7 +14,8 @@
 
   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.
 
   linux/include/linux/rbtree.h