Fix php.net link to open in a new window

Summary:
From @chad. This setup link should open in a new window so you don't lose your context in resolving setup issues.

@chad, this was the only one I could find immediately, let me know if you remember seeing others that I missed.

Test Plan: Faked an error, clicked the link, got a new tab.

Reviewers: chad, btrahan

Reviewed By: chad

CC: chad, aran

Differential Revision: https://secure.phabricator.com/D7991

src/applications/config/view/PhabricatorSetupIssueView.php

@@ -318,9 +318,14 @@ final class PhabricatorSetupIssueView extends AphrontView {
       array(),
       pht(
         'You can find more information about PHP configuration values in the '.
-        '<a href="%s">PHP Documentation</a>.',
-        'http://php.net/manual/ini.list.php',
-        hsprintf('')));
+        '%s.',
+        phutil_tag(
+          'a',
+          array(
+            'href' => 'http://php.net/manual/ini.list.php',
+            'target' => '_blank',
+          ),
+          pht('PHP Documentation'))));
 
     $info[] = phutil_tag(
       'p',