undoing #1781 change. It is breaking rtl

Author: akiran

src/inner-slider.js

@@ -705,7 +705,7 @@ export class InnerSlider extends React.Component {
 
     let innerSliderProps = {
       className: className,
-      dir: this.props.rtl ? "rtl" : "ltr",
+      dir: "ltr",
       style: this.props.style
     };