Update vertical scroll state when contentFrameWidth changes

A wider content frame can mean the horizontal scrollbar gets hidden,
which could in turn mean we need to adjust the scrollTop because the
clientHeight changed.

src/text-editor-presenter.coffee

@@ -487,6 +487,7 @@ class TextEditorPresenter
   setContentFrameWidth: (contentFrameWidth) ->
     unless @contentFrameWidth is contentFrameWidth
       @contentFrameWidth = contentFrameWidth
+      @updateVerticalScrollState()
       @updateHorizontalScrollState()
       @updateScrollbarsState()
       @updateContentState()