fix crashes on certain old android devices

src/framework/backend_glutin.rs

@@ -122,6 +122,8 @@ fn get_insets() -> GameResult<(f32, f32, f32, f32)> {
         let mut elements = [0; 4];
         vm_env.get_int_array_region(field, 0, &mut elements)?;
 
+        vm_env.delete_local_ref(field.into());
+
         Ok((elements[0] as f32, elements[1] as f32, elements[2] as f32, elements[3] as f32))
     }
 }