Fixes a typo

Signed-off-by: Jon Stovell <jonstovell@gmail.com>

Author: Sesquipedalian

Sources/Actions/AttachmentApprove.php

@@ -100,7 +100,7 @@ public function execute(): void
 
 		while ($row = Db::$db->fetch_assoc($request)) {
 			// We can only add it if we can approve in this board!
-			if ($allowed_boards = [0] || \in_array($row['id_board'], $allowed_boards)) {
+			if ($allowed_boards === [0] || \in_array($row['id_board'], $allowed_boards)) {
 				$attachments[] = $row['id_attach'];
 
 				// Also come up with the redirection URL.