Remove Date from Diff hovercard

Summary: Fixes T6184. On a Revision page we don't show the date as an important piece of information, so it's also not likely useful on a Hovercard (and confusing as to what the date means).

Test Plan: Hover over a linked Diff

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T6184

Differential Revision: https://secure.phabricator.com/D10579

src/applications/differential/event/DifferentialHovercardEventListener.php

@@ -56,9 +56,6 @@ final class DifferentialHovercardEventListener
     $hovercard->addField(pht('Author'),
       $handles[$rev->getAuthorPHID()]->renderLink());
 
-    $hovercard->addField(pht('Date'),
-      phabricator_datetime($rev->getDateModified(), $viewer));
-
     $hovercard->addField(pht('Reviewers'),
       implode_selected_handle_links(', ', $handles, $reviewer_phids));