Fixes #12128.  Remove redundant dojo/_base/fx dependency from HorizontalSlider.  dojo/_base optionally (based upon isBrowser) requires _base/browser which in turn requires dojo/_base/fx.
Fixes #12128.  Remove redundant dojo/_base/fx dependency from HorizontalSlider.  dojo/_base optionally (based upon isBrowser) requires _base/browser which in turn requires dojo/_base/fx.

git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@23467 560b804f-0ae3-0310-86f3-f6aa0a117693

redaktor/deliteful