Send stop inconditonnaly

chess_uci/src/lib.rs

@@ -365,13 +365,8 @@ impl<Fi: Read, Fo: Write> UciEngine<Fi, Fo> {
         }
     }
     pub fn stop(&mut self) -> Result<(), &'static str> {
-        match self.player[self.side_to_move().to_index()] {
-            Player::Human { .. } => Err("Not a machine to play for current color."),
-            Player::Engine { .. } => {
-                self.push(GuiCommand::Stop);
-                Ok(())
-            }
-        }
+        self.push(GuiCommand::Stop);
+        Ok(())
     }
 }