DB/Spells: add Dalaran Brilliance to spell power stacking rules group

sql/updates/world/custom/custom_2019_05_15_02_world.sql

@@ -0,0 +1,4 @@
+DELETE FROM `spell_group` WHERE `spell_id` IN (79038, 79039) AND `id`= 1134;
+INSERT INTO `spell_group` (`id`, `spell_id`) VALUES
+(1134, 79038),
+(1134, 79039);