[css-writing-modes] Remove issue on writing mode wrt table cells per WG resolution. <https://lists.w3.org/Archives/Public/www-style/2015May/0313.html>

Author: fantasai

css-writing-modes/Overview.bs

@@ -785,7 +785,6 @@ Block Flow Direction: the 'writing-mode' property</h3>
   Animatable: no
   Canonical order: n/a
   </pre>
-  <p class="issue"><a href="https://lists.w3.org/Archives/Public/www-style/2015Apr/0387.html">Proposal to defer orthogonal table cells</a> not resolved yet
 
   <p>This property specifies whether lines of text are laid out horizontally
     or vertically and the direction in which blocks progress. Possible