Scripts/Stratholme: Fix a DB error

Ref #20749

(cherry picked from commit be56a4669e)

sql/updates/world/master/2021_03_18_04_world_2017_12_21_02_world.sql

@@ -0,0 +1,2 @@
+-- 
+UPDATE `creature_template` SET `npcflag` = `npcflag` | 2 WHERE `entry` = 16031;

src/server/scripts/EasternKingdoms/Stratholme/instance_stratholme.cpp

@@ -171,6 +171,7 @@ class instance_stratholme : public InstanceMapScript
                         break;
                     case NPC_YSIDA:
                         ysidaGUID = creature->GetGUID();
+                        me->RemoveNpcFlag(UNIT_NPC_FLAG_QUESTGIVER);
                         break;
                 }
             }