Core/Spells: Allow skipping automatic removal of auras from spell_area when condition is no longer met (mostly used for cosmetic cutscenes after quest completion)

sql/updates/world/custom/custom_2020_01_11_00_world.sql

@@ -0,0 +1,2 @@
+ALTER TABLE `spell_area` CHANGE `autocast` `flags` TINYINT(3) UNSIGNED NOT NULL DEFAULT '3' AFTER `gender`;
+UPDATE `spell_area` SET `flags`=`flags` | 2;