Fixed syntax error in migration; thanks to Jochen Lienhard.

module/VuFind/sql/migrations/pgsql/3.0/004-modify-seach-columns.sql

@@ -3,5 +3,7 @@
 --
 
 ALTER TABLE "search"
-  ALTER COLUMN created TYPE timestamp NOT NULL SET DEFAULT '1970-01-01 00:00:00',
-  ADD COLUMN checksum int DEFAULT NULL;
+   ALTER COLUMN created TYPE timestamp,
+   ALTER COLUMN created SET NOT NULL,
+   ALTER COLUMN created SET DEFAULT '1970-01-01 00:00:00',
+   ADD COLUMN checksum int DEFAULT NULL;