Fix some gcc 7.3 reported warnings

```
src/client/joystick_controller.h:85:2: warning: duplicate 'virtual' declaration specifier [-Wduplicate-decl-specifier]
        virtual bool isTriggered(const irr::SEvent::SJoystickEvent &ev) const;
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/7.3.1/../../../../include/c++/7.3.1/ext/new_allocator.h:140:22: warning: destructor called on non-final 'JoystickAxisCmb' that has virtual functions but non-virtual destructor [-Wdelete-non-virtual-dtor]
                destroy(_Up* __p) { __p->~_Up(); }
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/7.3.1/../../../../include/c++/7.3.1/ext/new_allocator.h:140:22: warning: destructor called on non-final 'JoystickButtonCmb' that has virtual functions but non-virtual destructor [-Wdelete-non-virtual-dtor]
        destroy(_Up* __p) { __p->~_Up(); }
```

diff --git a/src/client/joystick_controller.h b/src/client/joystick_controller.h
index 6bea282eeb3a19d0fb307ce20bafa7da3194edae..7baacd81b0a57a3b2d46b4078c87e4bbef826dfa 100644 (file)
--- a/src/client/joystick_controller.h
+++ b/src/client/joystick_controller.h
@@ -60,6 +60,8 @@ struct JoystickButtonCmb : public JoystickCombination {
                this->key = key;
        }
 
+       virtual ~JoystickButtonCmb() = default;
+
        virtual bool isTriggered(const irr::SEvent::SJoystickEvent &ev) const;
 
        u32 filter_mask;
@@ -78,7 +80,9 @@ struct JoystickAxisCmb : public JoystickCombination {
                this->key = key;
        }
 
-       virtual bool isTriggered(const irr::SEvent::SJoystickEvent &ev) const;
+       virtual ~JoystickAxisCmb() = default;
+
+       bool isTriggered(const irr::SEvent::SJoystickEvent &ev) const override;
 
        u16 axis_to_compare;