Fix E_WARNING from r99863

diff --git a/includes/UserMailer.php b/includes/UserMailer.php
index ad713ef..3a3cca5 100644 (file)
--- a/includes/UserMailer.php
+++ b/includes/UserMailer.php
@@ -158,7 +158,7 @@ class UserMailer {
                global $wgEnotifMaxRecips, $wgAdditionalMailParams;
 
                $emails = '';
-               wfDebug( __METHOD__ . ': sending mail to ' . is_array( $to ) ? implode( ', ', $to ) : $to . "\n" );
+               wfDebug( __METHOD__ . ': sending mail to ' . ( is_array( $to ) ? implode( ', ', $to ) : $to ) . "\n" );
 
                $headers['From'] = $from->toString();
                $headers['Return-Path'] = $from->toString();