py-smbus: Fix FSF address in smbusmodule.c

The Free Software Foundation address was outdated. Discovered by
Fedora's rpmlint. The current address can be found at:
https://www.gnu.org/licenses/old-licenses/gpl-2.0.html#SEC4

Signed-off-by: Ondřej Lysoněk <olysonek@redhat.com>
1 file changed