adjust CreatureGroups to use cmangos flags (for already-supported values, no functionality changed)

sql/updates/world/4.3.4/2017_07_03_01_world.sql

@@ -0,0 +1,2 @@
+--
+UPDATE `creature_formations` SET `groupAI`=(`groupAI`&~0x004)|0x200 WHERE `groupAI`&0x004;

src/server/game/Entities/Creature/CreatureGroups.h

@@ -29,7 +29,7 @@ enum GroupAIFlags
     FLAG_MEMBERS_ASSIST_LEADER = 0x00000001,                                                // The member aggroes if the leader aggroes
     FLAG_LEADER_ASSISTS_MEMBER = 0x00000002,                                                // The leader aggroes if the member aggroes
     FLAG_MEMBERS_ASSIST_MEMBER = (FLAG_MEMBERS_ASSIST_LEADER | FLAG_LEADER_ASSISTS_MEMBER), // every member will assist if any member is attacked
-    FLAG_IDLE_IN_FORMATION     = 0x00000004,                                                // The member will follow the leader when pathing idly
+    FLAG_IDLE_IN_FORMATION     = 0x00000200,                                                // The member will follow the leader when pathing idly
 };
 
 class Creature;