fix(upgrade): move traps_group foreign key recreation at the end of upgrade script

www/install/php/Update-2.8.14_to_2.8.15.php

@@ -48,12 +48,6 @@ if (isset($pearDB)) {
             "  `traps_group_id` INT NOT NULL AUTO_INCREMENT"
         );
 
-        $pearDB->query(
-            "ALTER TABLE `traps_group_relation` " .
-            "ADD CONSTRAINT `traps_group_relation_ibfk_2` " .
-            "FOREIGN KEY (`traps_group_id`) REFERENCES `traps_group` (`traps_group_id`) ON DELETE CASCADE"
-        );
-
         $pearDB->query(
             "ALTER TABLE `traps_group` ADD PRIMARY KEY (`traps_group_id`)"
         );
@@ -63,5 +57,10 @@ if (isset($pearDB)) {
             "  DROP KEY `traps_group_id`"
         );
 
+        $pearDB->query(
+            "ALTER TABLE `traps_group_relation` " .
+            "ADD CONSTRAINT `traps_group_relation_ibfk_2` " .
+            "FOREIGN KEY (`traps_group_id`) REFERENCES `traps_group` (`traps_group_id`) ON DELETE CASCADE"
+        );
     }
 }