savestate: Remove now unnecessary compiler feature

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>

savestate/src/lib.rs

@@ -13,8 +13,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-#![feature(debug_non_exhaustive)]
-
 /// Nintendo Pokemon gen1 save state handling, based on
 /// https://bulbapedia.bulbagarden.net/wiki/Save_data_structure_in_Generation_I
 mod error;