Enabled tables in showVertex action

Tables have been out of developer preview for a while and they work
fine, so this change enables them for surfaces which have the
SCREEN_OUTPUT capability.

Change-Id: I333bc92628b52ebc2e6b06a0cbe6b9242018b334
diff --git a/assistant_callback.php b/assistant_callback.php
index aca4d9a..0862d78 100644
--- a/assistant_callback.php
+++ b/assistant_callback.php
@@ -149,7 +149,7 @@
     } else {

       arsort($neighbors);

       $params = array("person" => $closest, "count" => (count($neighbors) == 1 ? $i18n->msg("count_singular") : $i18n->msg("count_plural", array("count" => count($neighbors)))));

-      /*if (conv::has("actions.capability.SCREEN_OUTPUT", $json)) {

+      if (conv::has("actions.capability.SCREEN_OUTPUT", $json)) {

         $items = [

           array(

             "simpleResponse" => array(

@@ -177,15 +177,14 @@
           $items[1]["tableCard"]["rows"][] = array("cells" => [array("text" => $neighbor), array("text" => (string)$votes)]);

         }

         conv::ask_custom($items);

-      } else {*/ // This code shows a table if the user has a screen, but

+      } else {   // This code shows a table if the user has a screen, but

                  // unfortunately tables are not public yet.

-                 // @TODO: Uncomment when tables are out of developer preview.

         $people = array_keys($neighbors);

         $people_string = comma($people);

         $params["edges"] = $people_string;

         $num = mt_rand(1, 3);

         conv::ask_followup($i18n->msg("edges_".$num, $params), $i18n);

-      /*}*/

+      }

     }

   } else {

     conv::ask_followup($i18n->msg("not_found", array("person" => $json["queryResult"]["parameters"]["Vertex"])), $i18n);