Fix the hidden x scrolling.

IPython/html/static/notebook/less/codemirror.less

@@ -50,9 +50,3 b''
     .border-radius(0)
 }
 
-// FIXME: This is a horrible workaround for CodeMirror bug #2562.
-// Let's try not to release 3.0 with this.
-
-.CodeMirror-vscrollbar, .CodeMirror-hscrollbar {
-    display: none !important;
-}

IPython/html/static/style/ipython.min.css

@@ -577,10 +577,6 b' div.input_area > div.highlight > pre {'
   border: 0;
   border-radius: 0;
 }
-.CodeMirror-vscrollbar,
-.CodeMirror-hscrollbar {
-  display: none !important;
-}
 /*
 
 Original style from softwaremaniacs.org (c) Ivan Sagalaev <[e-mail]>

IPython/html/static/style/style.min.css

@@ -9071,10 +9071,6 b' div.input_area > div.highlight > pre {'
   border: 0;
   border-radius: 0;
 }
-.CodeMirror-vscrollbar,
-.CodeMirror-hscrollbar {
-  display: none !important;
-}
 /*
 
 Original style from softwaremaniacs.org (c) Ivan Sagalaev <[e-mail]>