Fix slider scroll via UI buttons

client/widgets/Slider.cpp

@@ -138,6 +138,10 @@ void CSlider::clickLeft(tribool down, bool previousState)
 			rw = pw / (pos.h-48);
 		}
 
+		// click on area covered by buttons -> ignore, will be handled by left/right buttons
+		if (!vstd::iswithin(rw, 0, 1))
+			return;
+
 		slider->clickLeft(true, slider->isMouseLeftButtonPressed());
 		scrollTo((int)(rw * positions  +  0.5));
 		return;