Fixed bug where new timeout prop passed to toastr update was ignored (#3164)

Author: tgreen7

packages/core/src/components/toast/toast.tsx

@@ -79,7 +79,9 @@ export class Toast extends AbstractPureComponent<IToastProps, {}> {
     }
 
     public componentDidUpdate(prevProps: IToastProps) {
-        if (prevProps.timeout <= 0 && this.props.timeout > 0) {
+        if (prevProps.timeout !== this.props.timeout && this.props.timeout > 0) {
+            this.startTimeout();
+        } else if (prevProps.timeout <= 0 && this.props.timeout > 0) {
             this.startTimeout();
         } else if (prevProps.timeout > 0 && this.props.timeout <= 0) {
             this.clearTimeouts();