Drop SCORE_DATETIME/NOW - all the databases we care about now support TIMESTAMP/CURRENT_TIMESTAMP

ext/image_hash_ban/main.php

@@ -31,7 +31,7 @@ class ImageBan extends Extension
             $database->create_table("image_bans", "
 				id SCORE_AIPK,
 				hash CHAR(32) NOT NULL,
-				date SCORE_DATETIME DEFAULT SCORE_NOW,
+				date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
 				reason TEXT NOT NULL
 			");
             $config->set_int("ext_imageban_version", 1);