Fix HUD climb/sink rate indicator direction.
Fix HUD climb/sink rate indicator direction.

hejunbok/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq